The purpose of this article is contributing to the historiography and history of Psychiatric Nursing in Rio Grande do Sul, Brazil by reconstructing the process that culminated in the closing of the Nursing Professional School, which functioned from 1939 to 1952, at Hospital São Pedro, Porto Alegre, Brazil. Documentary research and oral history were the primary sources of information. The reports of various witnesses of this process helped to detect the diverse political-partidary, corporative and inter-institutional factors that led to the extinction of that establishment.24226-37