Cholesterol embolism after left heart catheterisation by the femoral approach was diagnosed in seven men (mean age 59.6 years) out of a total of 4587 catheterisations. Diabetes was present in four patients, systemic hypertension in three, and signs of extensive atherosclerosis in six; five patients were taking anticoagulant drugs. Acute pain in the legs or abdomen occurred in six patients, two of whom had abdominal angina; renal failure was present in six patients, cutaneous manifestations in five, and a cholesterol embolus was seen in the retina in one. Six out of six patients had an appreciable increase in the erythrocyte sedimentation rate and five out of five had eosinophilia within a week of catheterisation. Renal failure was progressive in five patients, one of whom required haemodialysis. Three patients required amputation of the toes because of gangrene. Four patients died within four and a half months of catheterisation from causes not directly related to cholesterol embolism. At necropsy cholesterol emboli were found in all four patients. Cholesterol embolism is a rare but serious complication of left heart catheterisation.