When a court finds infringement, the infringer usually must pay damages to the patent holder, either in the form of actual damages or a reasonable royalty for the unauthorized use. Actual damages include lost profits the patent holder would have realized but for the infringement, while a reasonable royalty depends on the type of product, other royalty arrangements, time remaining on the patent, and other issues. In addition to damages, the prevailing party is also entitled to costs. Costs include court filing fees and related litigation expenses.

In addition to infringement damages, a patent owner may stop the infringer from continuing to produce infringing products. The court typically, as a matter of course, issues a permanent injunction after the infringer is held liable for violating the patent. In some instances, the patent holder will seek a preliminary injunction at the outset of the lawsuit where he or she can show no detriment to the public interest if the injunction is granted, a substantial likelihood of success on the merits of the case, and more compelling hardship for the patent holder if the infringer continues his or her activities while the case proceeds. The patent holder will find it difficult to get a preliminary injunction unless a prior adjudication proved the validity of the patent.

The combination of federal court jurisdiction, complicated subject matter, and technical underpinnings of patent law mean that patent holders and accused infringers should seek highly skilled legal help. Patent attorneys can assist litigants in developing their cases and in securing aggressive litigation services.