The diseases of the urinary apparatus are frequently-enough inside the locked-up spaces of the penitentiaries. Among them, glomerulonephritis and pyelonephritis take a special place, by their late diagnosis and their lasting evolution. The authors clinically and paraclinically investigated a number of 214 locked-up male persons aged between 18-57 years, presenting various clinical forms of glomerulonephritis. Histopathological exams performed in 51 patients confirmed the diagnosis.