The task of organizing inmates’ records at Florianópolis Penitentiary, begun in 2012, has made possible many studies addressing social control. Among the emerging matters, the issue of minors against the law is a real concern. From this Institution’s opening in 1930 to the creation of a Minors’ Housing in 1940, underage offenders were sentenced to imprisonment at this penitentiary. This article brings into focus the institutional dynamics and its biopower and normalization strategies.