To view full-year patstats data, click here:

Composite Table for 2000-2004
2005 (including cites to caselist)
2006 (including cites to caselist)


Cumulative Case List




To view quarterly patstats data with cites to caselist, click here:

First Quarter 2006
Second Quarter 2006
Third Quarter 2006
Fourth Quarter 2006
First Quarter 2007

Second Quarter 2007






To view Special Patent Report Information, click here:

of patent suits vs. number of util. patents issued
Patent Suits and Other Civil Actions, Over Time
Settlement Rates for patent cases
Sampling of 2004-05 Patent Suits






Jeffrey Johnson, Editor in Chief
Ali Dhanani, Associate Editor
Joan Beckner, Rule 36 Case Editor

Kenneth Liu
Iftikhar Ahmed
Student Editors

Prof. Paul M. Janicke, Faculty Coordinator

Comment on the 2006 rulings: The most striking feature of the 2006 rulings is the continued poor results for patentees on the infringement issue. On literal infringement there were 182 rulings for accused infringers and only 57 for the patent owners. At the appellate level the score was 80 to 16; at the lower tribunal level it was 102 findings of noninfringement to 42 findings of noninfringement. This continues a trend that is now of many years standing, the reasons for which are not entirely clear. It may result from patent owners' attempts to overstretch claim coverage, or from a desire by district judges to dispose of patent cases expeditiously (note the 82 summary judgments of noninfringement, most of which were case-dispositive rulings). Patentees are also winning summary judgments on the infringement issue (30 reported in 2006), but for them such rulings are often not dispositive. Validity and enforceability issues typically remain before a judgment can be entered.

Rulings on doctrine of equivalents infringement are even worse for patent owners, 109 to 14, again continuing a long trend.

Note on our additional postings: You may notice at the top of this page some links to special statistical information compiled by Professor Janicke in connection with studies on current trends in United States patent litigation. It is our intention to post additional tables of this type from time to time as information becomes available.


Regular patstats service: The University of Houston Law Center's Institute for Intellectual Property and Information Law is pleased to provide quarterly research information on recent patent law decisions in United States courts. Our reports began with the first quarter of 2000. We portray data on all reported patent decisions, including those affirmances decided by the Federal Circuit under Rule 36 with no published opinion. We track the cases on an issue-specific basis, e.g., public use bar under 35 U.S.C. 102(b) [issue 03], or infringement under the doctrine of equivalents [issue 24], or inequitable conduct [issue 17]. A complete list of tracked issues appears in Table 1 below. We hope to provide scholars, commentators, and practitioners with valuable data on trends in the enforcement side of patent law, to complement published data from other sources regarding the filing of patent applications and the issuance of patents. Beginning with the first quarter of 2005, we have posted a caselist identifying the cases from which our statistics are drawn. Each case on the list has an index number. Next to each entry in patstats there is a bracketed string of smaller numerals identifying the cases that make up the entry. For example, if there were 7 patentee victories on the public use issue, the entry might read: P: 7 [33, 38, 66(3), 74(2)]. This signifies that case numbers 33, 38, 66, and 74 were the cases in which these seven patentee victories on public use occurred. Recall that patstats counts successes patent-by-patent. Case 66 involved public use holdings on three different patents and case 74 involved public use holdings on two patents.

We report only on the current highest level decision in a given case, and we discard earlier rulings. For example, if a district court held a patent valid, but the court of appeals later held it invalid, we will include the appellate ruling in our current data and delete the district court ruling if it was included in any prior reported data. We will likewise go back and delete a statistic when a court of appeals opinion is withdrawn in order to rehear the case en banc. A new statistic will appear when the en banc decision comes down. Thus, we are always reporting the highest level of decision thus far reached in a given case, and past reports are subject to later adjustment.

In the full-year data tables we include, in addition to won-lost results, information on how the results were reached, namely, whether by appellate affirmance or reversal, and whether the trial-court ruling was based on a summary judgment or a judgment following trial. (A substantial majority of patent cases decided by the Federal Circuit are on appeals from summary judgments.)

We do not attempt to gather data on unreported district court cases. We do include in our data non-precedential decisions and Rule 36 summary affirmances by the Federal Circuit. For the Rule 36 cases we determine the affirmed points by inspecting the appellate briefs.

We include reported cases decided by the International Trade Commission and the Court of Federal Claims as well as district court cases. However, we do not report on decisions of the Patent & Trademark Office Court of Federal appeals therefrom. And we do not attempt to collect data on unreported district court patent decisions. We do not differentiate between precedential and non-precedential opinions.

We report each issue that has been decided. Where multiple patents are litigated and decided, we report each as a separate item. We do likewise where different claims of a patent are adjudicated in different ways, e.g., claim 1 invalid for on-sale bar, and claim 19 invalid for obviousness. Hence a given case is apt to generate four or five data items, perhaps more. It is therefore not valid to conclude from these data that patentees won or lost a certain number of "cases," or that the accused infringers did so.

1. Mr. Johnson is Research Adjunct Professor of Law at the University of Houston Law Center and an attorney at the Houston office of Mayer Brown Rowe & Maw. Mr. Dhanani is an attorney at the Houston office of Baker Botts. Ms. Beckner is an attorney at the Houston office of Howrey LLP. Professor Janicke is the HIPLA Professor of Law at the University of Houston Law Center.


Validity rulings --

  1. 102(a) -- prior public knowledge or publication
  2. 102(b) -- time-bar publication or patent
  3. 102(b) -- public use
  4. 102(b) -- on sale
  5. 102(c) -- abandonment
  6. 102(d) -- prior foreign patenting
  7. 102(e) -- earlier-filed US patent of another
  8. 102(f) -- derived subject matter; wrong inventorship
  9. 102(g) -- prior invention by another
  10. 103 -- obviousness
  11. 112, inadequate disclosure -- description
  12. 112, inadequate disclosure -- enablement
  13. 112, inadequate disclosure -- best mode
  14. 112, claim indefinite
  15. Double patenting
  16. Improper broadening


Enforceability rulings --
  1. Inequitable conduct
  2. Misuse

Procedural rulings --

  1. Laches
  2. Equitable estoppel
  3. Limitations
  4. Failure to mark


Infringement issues --

  1. Literal direct infringement
  2. Doctrine of equivalents direct infringement
  3. Inducing infringement
  4. Contributory infringement
  5. Selling or importing product of patented process
  6. Shipping abroad ( 271(f) or (g))
  7. License defense
  8. Exhaustion defense
  9. Exemption under 271(e)
  10. Exemption for other experimentation


Damages calculations --

  1. Lost profits
  2. Reasonable royalty
  3. Split bases


Special Factors rulings --

  1. Willfulness
  2. Enhanced damages due to willfulness
  3. Attorney fees to patentee
  4. Attorney fees to accused infringer
  5. Preliminary injunction


Addressing Claim Interpretation

Claim interpretation issues are often difficult to characterize the district court's construction solely as for plaintiff or for defendant. We tried for a time to categorize claim-interpretation decisions as being "for the patentee" or "for the accused infringer," but this proved unfeasible and we have discontinued claim interpretation as a separately reported issue. It is safe to say that it is an important contested point in nearly all infringement decisions and some validity rulings.

Some Caveats

While we believe it is important for actual and potential litigants and their attorneys to know what has been happening recently in the courts on various patent law points, the value of statistics can easily be exaggerated. We caution that any set of statistics should be used with care, in that it is not always apparent what the data may signify. Shifting figures for court results on a particular issue may reflect not so much a predisposition of a court as they do variations in the strengths of positions that litigants bring to that court. For example, if patentees are more often willing to litigate the on-sale issue on weaker facts than at some previous time, we should expect to see a decrease in the percentage of times the patentee prevails on that issue, regardless of any judicial attitudes on the subject. If defendants become more selective in their use of the inequitable conduct defense, we should expect to see a rise in their success rate on that point, again independent of any shift in judicial attitude. Moreover, since very few issued patents are actually litigated to judgment, the reported statistics do not necessarily reflect on the overall quality of patents being issued by the Patent and Trademark Office, but at most only the quality of those chosen by litigants to be asserted in lawsuits.

Among the inherent weaknesses in our reported data, we do not include unreported district court decisions, and these could represent final decisions in some cases. Another weakness is that for practical efficiency reasons we do not monitor for certain issues at all, and these include some important litigation issues, such as subject matter jurisdiction, in personam jurisdiction, venue, necessary parties, discovery, sanctions (other than attorney fees and damages enhancement), and costs.

Please refer any questions to the IPIL Program Coordinator at the following e-mail address: