Method of treating benign prostatic hyperplasia

Methods of treatment of benign prostatic hyperplasia are disclosed. One method includes orally administering to a patient having benign prostatic hyperplasia an alpha-1 adrenoceptor blocking agent, and orally administering to the patient a therapeutically effective amount of 13-cis-retinoic acid. Another method includes orally administering to a BPH patient an inhibitor of steroid 5(alpha)-reductase, and orally administering to the patient a therapeutically effective amount of 13-cis-retinoic acid. The methods further include an initial treatment of patients with an initial dosage of about 0.25 mg per pound of body weight of 13 cis-retinoic acid daily for a period from about ten days to about twenty days, and followed by a sustaining treatment of the patients with a sustaining dosage of about 0.25 mg per pound of body weight of 13 cis-retinoic acid about every five to seven days in a sustaining period.