This study aims to offer a historical overview of the emergence and evolution of group psychotherapy, tracing its roots, main models and theoretical bases. Its origin goes back to the beginning of the past century (1905), after which it evolved for five decades: the formative years. Further on, during the 50's and 60's, group psychotherapy went through a period of theoretical expansion, followed by a period of consolidation in the 70's, and maturation in the 80's and 90's. Finally, the study examines its recent evolution, highlighting the construction of new models. In the last few years, several treatment techniques have been developed to attend specific patient populations, with a variety of medical and psychosocial conditions, which suggests an increasing tendency towards a greater specificity of its application.