This manuscript presents the first comprehensive systematization of Gestalt therapy methodology with the aim of providing a shared foundation for clinical research. While Gestalt therapy is widely practiced, its recognition as an evidence-based method has been hindered by the lack of a coherent methodological framework. The book addresses this gap by identifying key methodological focal points that allow for the study of therapy effectiveness through both qualitative and quantitative research, while also demonstrating ways of integrating Gestalt methodology into modern healthcare systems and adjacent disciplines such as sociology, anthropology, clinical psychology, psychiatry, and other psychotherapies.