Overcrowding is a problem in the Prison System in Minas Gerais, in Brazil, and in much of the world. This study sought to register the vision of the senior management of the State Department of Prison Administration (SEAP) regarding the consequences of overcrowding for the operation and management of prison units in the State of Minas Gerais. For this, it was traced a general panorama of the prison systems of the federative units of Brazil and, in more detail, of the prison system of Minas Gerais, where it is possible to understand the trajectory of the system, its expansion, and also the evolution of its prison population. A descriptive, exploratory research with a qualitative approach was carried out, combining documentary and bibliographic analysis with participant observation and semi-structured interviews with SEAP managers. The results of the research point to the conclusion that the consequences of overcrowding are broad and interconnected, the main one being the great difficulty of the system to carry out the determinations of the Law of Criminal Enforcement, in order to ensure not only the custody and safety of prisoners, but also their effective re-socialization.