Dialysis patients often suffer from erectile dysfunction. The prevalence of this symptom in the context of dialysis is as high as 90%. Diabetes, diffuse vascular disease and pharmacological therapy are attendant causes of this condition, severely impairing the quality of life. Due to the high frequency of erectile dysfunction in uremic patients, minimalist diagnostic approaches are often used. Nevertheless, a careful differential diagnosis is also warranted in well dialyzed patients to identify causes and corrigible patterns. The case reported here exemplifies this critical issue. A 44 year old obese diabetic patient complained about the recent onset of erectile dysfunction. On examination, the penile echo- Doppler was normal, and suggested a cause other than diabetic vascular disease. The high dialysis efficiency (daily hemodialysis, flexible schedules, EKRc from 15 to 25 ml/min) warranted the same diagnostic work-up as would adopted for non-uremic patients. Whilst the rising prolactine level (76.1 μg/l and 129 ng/ml) was still in the range commonly found in dialysis patients, a nuclear magnetic resonance examination was carried out and led to the identification of prolactinoma. Therapy with cabergoline was found effective and sexual potency was restored. Normalization of hormonal patterns followed within 2 months. This is the first case so far reported in a daily dialysis patient. It underlines the importance of a non-minimalist approach to the problem of sexual disorders in renal replacement therapy (RRT) patients, at least when dialysis efficiency is high and onset is rapid. It also suggests considering prolactinoma as an emerging diagnosis in the general population, which can be detected by the use of sensitive imaging techniques in the differential diagnosis of this condition.