Patent litigation attorney in Paris

Attorney at law or patent attorney?

Dhenne Avocats is a French law firm dedicated to patents. We act for manufacturers, laboratories, technology companies, innovative SMEs and inventors, for claimants and defendants alike, before the Paris Judicial Court and before the Unified Patent Court.

The question comes up at almost every first meeting. The two professions are complementary and do not perform the same office.

The French patent attorney drafts and files patent applications, conducts proceedings before the INPI and the European Patent Office, and monitors portfolios and renewal fees. The attorney at law represents clients in court: bringing and defending actions, pleading, and taking charge of procedural strategy. Before the Paris Judicial Court, representation by an attorney at law is mandatory.

Our firm does not draft or file patent applications. We work with our clients' patent attorney , or with one of those we regularly instruct. That division of labour is an asset rather than a constraint: the patent attorney knows the patent, the litigator knows the judge.

The disputes we conduct

Infringement action, from establishing the infringement through to the assessment of damages.
Defence of the accused company, including by challenging the validity of the patent.
Revocation action and counterclaim for revocation.
Saisie-contrefaçon, for claimants and defendants alike, sequestration and trade secrets.
Provisional measures and preliminary injunctions, particularly in pharmaceutical matters.
FRAND licences and standard essential patents .
Employee inventions: additional compensation, fair price, referral to the National Commission.
Supplementary protection certificates and pharmaceutical litigation.
Arbitration and mediation, where the global dimension of the dispute lends itself to it.

The detail of the procedures, the time limits and the strategic options is set out on our patent litigation.

Which courts

In France, the Paris Judicial Court has exclusive jurisdiction in patent matters, with appeals heard by the Paris Court of Appeal. That concentration is a French peculiarity: it produces a dense body of case law, handed down by specialist judges, which has to be followed decision by decision.

Since 1 June 2023, the Unified Patent Court rules on infringement and validity of European patents for all participating States in a single set of proceedings. Matthieu Dhenne is registered there as a UPC Representative. The choice between the French route and the unitary route, like the choice of anopt-out, is decided case by case and before the first step is taken.

Technical fields

Patent litigation is won first on the technology. We act in computing and computer-implemented inventions, in telecommunications and standard essential patents, in chemistry and life sciences, on medical and electronic devices, and in mechanical engineering.

Electronics

FRAND licenses

Pharmaceuticals

Medical devices

Telecommunications

Chemistry

Biotechnology

Mechanics

A boutique, not a department

The firm is a structure dedicated to patent litigation. The partner who takes the case is the one who argues it. That organisation limits conflicts of interest, which matters when the opponent is a group already advised by the full-service firms.

It rests on continuous scholarly work. Matthieu Dhenne has been a member of the Paris Bar since 2014 and holds a doctorate in patent law from Paris 2 Panthéon-Assas University. He co-authored a patent law treatise published in 2024 and contributes regularly to the Kluwer Patent Blog. The firm and its founder are recommended by IAM Patent 1000 and by IP STARS in 2026, and distinguished in the Palmarès du Droit 2026 for patent litigation.

Contact us

A cease and desist letter received, a competitor copying, a saisie announced, a patent to be brought down: the earlier the firm is instructed, the more options stay open. Talk to us.

Avant tout litige, deux programmes permettent d’anticiper : la litigation readiness for patent disputes et la construction d’un portefeuille de brevets défendable. Une second opinion peut aussi éclairer un dossier déjà engagé.