Clofibrate, a drug with lipid-lowering and anticoagulant properties, is being used extensively in the treatment of atherosclerosis. Few toxic effects result from regular doses in man or large amounts in animals; effects of large quantities in man are unknown. A 15-year-old boy who took 49 capsules of clofibrate is, to our knowledge, the first known instance of attempted suicide with this medication. He showed no clinical or laboratory evidence of harm from this large amount, and remained asymptomatic during the entire period of observation.