A patent is a right that enables its holder to exclusively exploit the invention to which it relates. Given the rapid development of technology, increasing knowledge and easier access to information, legislation had to adapt to modern times and protect inventors in order to encourage them to continue creating. Patent is recognized and declared invalid by the State intellectual property office conducting administrative procedure. The thesis focuses on cases in which other persons have violated the patent by unauthorized actions regarding the invention protected by the patent and what legal remedies are available to its holder. At his disposal are civil law claims, which are realised in civil proceedings, such as claim for declaration and cease of violation or claim for compensation for damages. There is the possibility of initiating criminal proceedure where the offender is threatened with a prison sentence, as well as misdemeanor proceeding in which sanctions are determined in form of fine. The thesis deals with the basic rules of the procedure, such as principles, rules on evidence and jurisdiction. It is possible for patent infringement to occur when there is an international element present, such as the residence of the defendant outside the Republic of Croatia, or when the infringement occurs on the territory of another country. In that case, the relevant rules are the rules of private international law. International treaties that regulate the patent law are of exceptional importance, as well as legislation o European Union, which speaks of the importance of regulating intellectual property at the international level.