Exposure of freshwater Indian catfish Heteropneustes fossilis to acute levels (0.048 mg/l) of chlordecone (Kepone) for 96 hours and to subacute levels (0.024 and 0.012 mg/l) for short-term (10 and 20 days) and long-term (30 and 60 days) periods resulted in markedly decreased total serum protein concentrations and hypercholesterolemia in the fish at all time intervals. However, fish exposed to sublethal concentration (0.008 mg/l) of chlordecone exhibited no significant changes in these parameters during either short- or long-term treatments.