Background.- Little is known about the natural history of erectile dysfunction. Erectile dysfuncti¬on is clearly a symptom of many conditions and certain risk factors have been identified, some of which may be emanable to prevention strategies. Among these, hypogonadism in association with a number of endocrinologic conditions have been demonstrated as a risk factor. Design.- Over a period of 7 years, from 1991 to 1998, 2750 men who had referred to our sexual dysfunctions center for erectile dysfunction have been evaluated. Sexual hystory, physical examina¬tion, hormonal evaluation (prolactin, free testos¬terone), Doppler ultrasound, intracavernous phar-macotest and if indicated DICC and neurologic evaluation have been performed. Data were analyzed from the files of the patients. Patients with endocrinological causes without other eti¬ology were included in the study group. The me¬an age of the patients were 39.2 (range 23-75). The therapy given and results of the therapy were analyzed. Results.-"Sexual history revealed 69/2750 (2.5 %) of the patients had primary impotence. 1100 (40.5%) patients were diabetic. Although diabe-tus mellitus is the most common endocrinologic cause of impotence, endocrine causes were detec¬ted in 190 patients (7%). In diabetic patients not only one factor could be determined as a cause of impotence. Cardiovascular disease was appearent in 495 patients (17.6%). Hormonal evaluation showed hyperprolactinemia in 19 of 190 (10%) patiens, hyperprolactinemia + androgen defici¬ency in 97 (50.8%), androgen deficiency in 74 (39.2%) patients. After the testosterone replace¬ment therapy, 49 (70%) of the patients reported increase in penile rigidity and seminal volume and were satisfied With the therapy while 21 (30%) of the patients needed self-injection pharmacothe-rapy. In patients with hyperprolactinemia, bro-mocriptine is used and only 16% of satisfactory results were obtained. Overall success rate was 37% with hormonal therapy. Conclusions.- Impotence is a major health con¬cern. There are many determinants related to the risk factors and not only one factor could be de¬termined as the etiological factor for erectile dys¬function. In patients with an etiology of endocri¬ne causes, hormonal therapy is advisable but furt¬her other therapies may also be needed in case of unsatisfaction.