Cerium nitrate (CN) is a nitrate of the rare earth metal which has been widely used for local treatment of severe bum injuries. The purpose of present study is to evaluate acute toxicity of the CN 0,04 M solution and sub-acute toxicity of gel CN 0,05 M prepared by the NIB in Wistar albino rats. Both acute and sub-acute studies were done according to the Organization for Economic Cooperation and Development (OECD). In the acute toxicity study, solution of CN were administered to six rats at dose of 2000mg/kg, the rats were observed for 24 hours. No toxic signs/mortality was observed. In the sub-acute study, solution CN 0,04 M (n=10) and gel CN 0,05 M (n=10) were administered once daily for 28 days to rats at dose of 1000mg/kg, orally. No toxic signs/mortality was observed. There were no significant changes (p 0.05) in the body weights, haemato-biochemical parameters. No gross/histopathological lesions were observed in liver, spleen and renals of the rats.