A program involving acute, subacute, and chronic toxicity as well as reproduction studies was performed to evaluate the potential toxicity of chenodeoxycholic acid in rats, hamsters, and dogs. Acute oral toxicity studies showed that there were some species differences and that female hamsters were more sensitive to toxic doses than male hamsters. Subacute and chronic studies in hamsters showed the toxicity to be limited to effects on the liver, including proliferation of intrahepatic bile ducts in portal areas with elevations of serum glutamic‐pyruvic transaminase and glutamic‐oxaloacetic transaminase. No tumorigenic effect was observed.