Snake bites are of major public health importance in Africa as a cause of morbidity and mortality. Echis ocellatus is responsible for the majority of envenomation cases in West Africa. Antivenom immunotherapy is the only specific treatment available for envenomed patients. From January 1997 to December 2001, 325 patients suffering from snake bites were enrolled in a survey undertaken at Goundi Hospital, Chad. We analysed the percentage of envenomed patients, sex distribution, distribution along the year, lethality, hospital stay and recovery clotting time. Two hundred and ninety-eight patients showed signs of envenomation and were treated with antivenom immunotherapy with three different sera in consecutive periods. Young males were more frequently involved. The overall lethality was 8%. Lethality and hospital stay were significantly different in the differently treated patients. Most of the data in our series were similar to those from other sub-Saharan countries but, overall, the percentage of snake bite victims who were admitted to hospital was higher.