The 24 hour lethal effects of cocaine were compared to those of a crude ethanol extract of the coca leaf (Erthroxylon coca) in male, Swiss mice. Various doses of cocaine HCl and coca leaf extracts suspended in a Tween 60, Arlacel 83, and distilled water vehicle were injected IP into groups of 10 mice. The LD50 for cocaine was 95.1 mg/kg. The LD50 for the coca extract was 3450 mg/kg. The LD50 of the extract based on its cocaine content was 31.4 mg/kg. The results clearly indicate that the coca leaf contains constituents other than cocaine that can contribute to a toxic effect of the plant.