This article discusses the contributions of neo-institutionalism to the Social Sciences and the study of social behavior. The research was carried out based on a literature review on the subject and concludes that the theoretical framework of the neo-institutional theory gives a new twist to the classical foundations of the Social Sciences, also being identified as institutionalist theory. Besides, this theoretical perspective offers instrumentsMoreover, this theoretical perspective offers instruments capable of contributing to the effectiveness of public policies, from diagnosis to execution, considering the transition institutions as effective mechanisms of institutionalization of new practices and capable of promoting effective institutional changes.Este artigo discute as contribuições do neo-institucionalismo para as Ciências Sociais e o estudo do comportamento social. A pesquisa foi realizada a partir da revisão bibliográfica sobre o tema e conclui que o arcabouço teórico da teoria neo-institucional dá nova roupagem aos clássicos fundadores das Ciências Sociais, sendo também identificados como teoria institucionalista. Além disso, tal perspectiva teórica oferece instrumental capaz de contribuir para a efetivação de políticas públicas, desde o diagnóstico à execução, considerando-se asinstituições de transição como mecanismos eficazes de institucionalização de novas práticas e capazes de promover mudanças institucionais efetivas.        This article discusses the contributions of neo-institutionalism to the Social Sciences and the study of social behavior. The research was carried out based on a literature review on the subject and concludes that the theoretical framework of the neo-institutional theory gives a new twist to the classical foundations of the Social Sciences, also being identified as institutionalist theory. Besides, this theoretical perspective offers instrumentsMoreover, this theoretical perspective offers instruments capable of contributing to the effectiveness of public policies, from diagnosis to execution, considering the transition institutions as effective mechanisms of institutionalization of new practices and capable of promoting effective institutional changes.