Wilson's disease is an autosomal recessive disorder of copper metabolism in individuals with mutant ATP7B genes. Impairment of normal excretion of hepatic copper results in toxic accumulation of the metal in liver, brain and other organs. Clinical manifestations include hepatic, neurologic or psychiatric disturbances. Penicillamine, as a chelator of copper, is the drug of choice in the treatment of Wilson's disease but after treatment of penicillamine, granulocytopenia, thrombocytopenia, the nephrotic syndrome, Goodpasture's syndrome, pemphigus vulgaris or pleural effusion may supervene. We report a case of macromastia with multiple fibroadenomas in a patient who was treated with penicillamine for Wilson's disease.