The article focuses on a less-discussed issue of social marginalization of people leaving penitentiaries, which is the prevalence of multifaceted health problems experienced by people in this category. It includes poor health status, resulting from, among others, poor housing conditions, harmful or risky lifestyle, and lack of access to medical services. Data from the District Inspectorate of the Prison Service in Lodz, Poland on the health conditions of inmates was accessed. These data were supplemented by qualitative research conducted in 21 juvenile detention centers and 8 prisons across the country, conducting direct observations and In-Depth Interviews (IDI). A total of 198 IDIs were conducted with incarcerated (72) and released (30) juvenile offenders, and incarcerated (68) and released (28) adult offenders. These were complemented by IDIs with experts (50) and Focus Group Interviews (FGIs; 8) with male and female inmates in 4 Polish prisons. The study revealed that mental and physical health is a serious obstacle to social reintegration of ex-prisoners. It is rarely addressed by state institutions. There are strong associations between neglect of health issues in the prison population and increasing social exclusion after leaving prison. As Poland has a restrictive penal policy, former prisoners remain a group with social stigma and little support.