Preliminary Injunctions in Patent Litigation

Austria has established itself as a highly regarded and efficient patent litigation jurisdiction within Europe. Patent infringement actions fall under the exclusive competence of the Commercial Court of Vienna, whose specialised panels consist of three professional judges with substantial experience in patent litigation.

A hallmark of the Austrian system is its strict bifurcation between infringement and validity. While infringement matters are handled by the Commercial Court of Vienna, invalidity (nullity) proceedings are decided separately by the Nullity Department of the Austrian Patent Office. Infringement courts may consider validity only to the extent necessary to decide whether to stay the proceedings, and even then, a stay is granted only when invalidity appears highly likely – reflecting a balanced but patentee‑sensitive approach.

Austria’s judiciary is recognised for its technical expertise, which is ensured through judical specialisation rather than technically qualified lay judges. Preliminary injunctions are a common and effective enforcement tool, supported by procedural rules that allow swift decisions subject to the requirement of timely action, and, in exceptional cases, even on an ex parte basis.

Triggers for seeking a preliminary injunction in Patent/SPC matters

As well as product launch, indications of imminent launch (e.g., by notification or response to a warning letter) will provide a strong case for a party seeking a preliminary injunction in patent & SPC related matters. Preliminary injunctions are more likely to be granted if, for example, the alleged infringing product has not yet been launched or has only very recently entered the market.

Timely action is a key requirement when seeking a preliminary injunction. A delay in filing may undermine the presumption of urgency and adversely affect the chances of success. A company should take steps without undue delay once it becomes aware of a concrete threat of patent infringement in Austria.

In the reverse situation, i.e., when a company expects a preliminary injunction from a competitor, there is no formal preparatory action, such as filing a protective letter with the court (which is possible in Germany, for example). Only a statement on an application for a preliminary injunction can be filed with the court, provided that this is permitted by the court.

Requirements of a preliminary injunction

In Austria, a preliminary injunction may be granted if the patentee credibly demonstrates a prima facie case of patent infringement and shows that immediate relief is necessary to prevent imminent harm. The patentee must present concrete factual submissions and supporting evidence indicating that the defendant`s conduct likely falls within the scope of the asserted patent. Full proof is not required at this stage, but speculative allegations are insufficient.

Although Austrian law does not provide for a formally defined urgency requirement, courts expect the patentee to act without undue delay once becoming aware of the infringement or the imminent threat thereof. A significant delay may lead the court to conclude that interim relief is not justified. In addition, the court will refuse or limit a preliminary injunction if the patent appears manifestly invalid; however, validity is assessed only on a prima facie basis, and a denial of relief requires that invalidity be highly likely.

Finally, the court balances the interests of the parties and may deny relief if the injunction would cause disproportionate hardship to the defendant or third parties. In exceptional cases, preliminary injunctions may be granted ex parte, or the patentee may be required to provide security to cover potential damages should the injunction later prove unjustified.

Is a bond or cross-undertaking payable when filing a preliminary injunction application?

Under Austrian law, a patentee seeking a preliminary injunction is not automatically required to provide a bond or cross-undertaking at the time of filing the application. As a rule, preliminary injunctions in patent matters may be granted without prior security, reflecting the court`s confidence in the provisional assessment of infringement and urgency.

However, Austrian courts have the discretion to order the provision of security if this appears necessary to protect the defendant against potential damages if the injunction is later found to have been unjustified. Such security is ordered only in exceptional circumstances, for example where the injunction would have particularly severe economic effects or where the patentee`s case appears less clear-cut.

Right to Appeal

Decisions granting or refusing a preliminary injunction may be appealed by either party. The appeal is heard by the Higher Regional Court of Vienna as the competent appellate court for preliminary injunction proceedings in patent matters. The appeal focuses on whether the first-instance court correctly applied the legal standards for interim relief and properly assessed the evidence submitted.

Filing an appeal does not automatically suspend enforcement of a granted preliminary injunction. A stay of enforcement may be ordered only in exceptional circumstances, typically subject to the provision of security. In practice, appellate proceedings are handled swiftly, reflecting the provisional nature of preliminary injunctions.

Recent Decisions/Developments

Austrian courts recognise a prima facie presumption of validity for granted patents in preliminary injunction proceedings. The mere existence of pending nullity or opposition proceedings does not bar interim relief; the respondent must credibly demonstrate that the patent is likely to be revoked in order to rebut this presumption (Higher Regional Court Vienna, case 33 R 72/22h, 31 October 2022). Courts emphasise that preliminary injunction proceedings must not turn into a 'mini nullity action'. While validity objections may be considered, this must be within the context of a summary and provisional review, which focuses on whether there is sufficient substantiation of serious doubts (Higher Regional Court Vienna, case 33 R 61/22s, 21 October 2022). The Vienna Court of Appeal has confirmed that new or substantially expanded technical attacks raised only at appeal stage are generally inadmissible, and that validity is assessed less extensively than in main proceedings (Higher Regional Court Vienna, 33 R 69/22t, 3 November 2022). The Supreme Court has recently reiterated that claim construction and technical assessment are largely case-specific and will be reviewed only in instances of a manifest error of assessment (Supreme Court, case 4 Ob 35/25p, 31 July 2025).

Security for damages in Austrian patent injunction proceedings

A preliminary injunction may be granted on the condition that the patentee provides security for potential damages. Austrian courts apply a graduated approach: where the potential disadvantage to the respondent cannot yet be reliably quantified, a relatively moderate security may suffice, expressly because security can later be increased if it proves insufficient. By contrast, where the factual situation is undisputed and the legal position is clear – such that a legal remedy against the injunction is unlikely to succeed – courts may dispense with security altogether (Higher Regional Court Vienna, 30 R 5/20f, 31 January 2020).

In patent cases, security is typically considered where the injunction results in market exclusion or disrupts established commercial or reimbursement structures. Reported cases demonstrate that security amounts in the six-figure range are required where concrete commercial exposure is evident. In high-value pharmaceutical disputes, security amounts of EUR 500,000 or more have been deemed appropriate (Supreme Court, case 17 Ob 5/11a, 16 February 2011).

Takeaways

Austria offers an efficient and reliable preliminary injunction system for patent matters. Timely action is essential, as undue delay may undermine the presumption of urgency. The presumption of patent validity supports patentees seeking interim relief, while courts carefully balance proportionality to ensure that injunctions do not cause disproportionate hardship to defendants or third parties.

For further details about patent law in Ireland, see our Patent Litigation Comparator Guide.