The author begins her work by pointing out how legal regulations remain closely connected with all areas of life, more specifically the fact that interdependence between social relations and civil procedure model can be noted. She points out that the massification of legal events and the resultant necessity to provide simultaneous legal protection to many entities is one of the biggest challenges that legal systems all around the world have been facing for a long time. She also notes that legal systems that want to reflect developments in society must first precisely identify the interests present therein and then recognize those worthy of legal protection. Among the interests protected by law is the group interest. In Polish legal system it is protected by the group proceedings. The author points out that the idea to afford legal protection to many entities in one proceedings was born in common law system and took a form of class action. She recalls the considerations that underpinned the introduction of class action and the purposes it was meant to serve. She also presents the grounds for initiating the class action and the Polish group proceedings. Noticing the differences between them, the author considers how they affect the effectiveness of protecting group interests in legal proceedings.