Twelve patients with benign breast disease (BBD) were treated with 150,000 IU of vitamin A daily taken orally. All patients were symptomatic and had measurable or evaluable breast masses. At 3 months of treatment, complete or partial responses were observed in five patients, and marked pain reduction in nine was observed. Side effects were generally mild in nature, consisting mostly of skin and mucosal changes, and were rapidly reversible upon discontinuation of the drug. Treatment was interrupted or discontinued in only two patients, and the dosage of vitamin A was reduced in one on account of toxicity. No hepatotoxicity was observed. Investigation of the chemopreventive role of either vitamin A or retinoids in patients with BBD who are at high risk of developing breast cancer is suggested.