From 1980 to 1997 we had observed 50 cases of cutaneous side effects of thiacetazone. There were 25 cases of Steven-Jonhson syndrome, 23 cases of Lyell syndrome, a case of erythrodermia and a case of lichenoid toxidermia. The mortality was 40% with 16 cases of Lyell syndrome and 4 cases of Steven Johnson syndrome. Thiacetazone is a minor tuberculostatic drug used widely in the national program against tuberculosis. Our results confirm the seriousness of cutaneous side effects due to this drug. So like in other neighboring countries, we suggest to avoid use of this drug in Senegal.