The sludge infected with Listeria monocytogenes bacteria (concn. 2.5-10(7) cfu/g) was treated with H2O2 in doses 39.71-158.57 g/kg d.m. of sludge or with mixts. of H2O2 and FeSO4, in doses 17.37-117.34 g/kg and 6.62-39.71 g/kg of sludge, resp. The total sludge disinfection was achieved only when doses of H2O2 and FeSO4, 117.34 and 39.71 g/kg d.m. of sludge, resp., were applied.