The article is dedicated to the investigation of the problem of liability for damages caused by the filing of a frivolous lawsuit. It analyzes the practice of UK courts that elaborated the doctrine of liability for malicious prosecution. This doctrine was initially used only in the event of unfounded allegations of criminal misconduct; however, in the case of Willers v. Joyce, the UK Supreme Court extended liability for malicious prosecution to civil lawsuits. The author reviews the arguments against the imposition of liability for a frivolous lawsuit that were expressed in the case of Willers v. Joyce and in the previous practice of UK courts and evaluates them in the context of Russian law. A consistent analysis of the arguments against recognizing the possibility of compensating for damages caused by a frivolous lawsuit leads the author to the conclusion that there are no significant obstacles to the adoption of the doctrine of liability for filing a frivolous lawsuit. This premise, in turn, reflects a more general idea of the substantive significance of procedural conduct.