A systematic review of the literature about the causal relationship between priapism and adrenergic a-blockers used for the treatment of lower urinary tract symptoms (LUTS) and arterial hypertension was accomplished. While opportunely describing a case of tamsulosin-induced priapism, we reviewed the literature using MEDLINE, COCHRANE and LILACS libraries, selecting all the articles until the present time addressing the association between priapism and a-blockers. Our patient was a healthy 32-year-old man who reported LUTS. His prostate was firm and moderately enlarged on digital rectal examination, measuring 30 grams on transabdominal ultrasound. Empirical treatment with tamsulosin was initiated and he developed priapism the day after the first dose of the drug. Erection was reverted by aspiration of the corpora and intracavernosal injection of adrenaline. Despite the late presentation (40 h of erection), he had no ED on follow-up. In the systematic review, among 2157 articles on priapism, only 13 similar cases reported a-blockers as the etiology of priapism. Therefore, adrenergic a-blockers are effective and safe drugs, with few serious adverse reactions. Nevertheless the association with priapism is well documented and related to substantial morbidity, this is an infrequent event and should not preclude their use, considering that the patient be sufficiently informed.