Mean platelet (PLT) activation has an important role in the development of vascular diseases. In this study, we aimed to investigate the PLT volume in patients with vasculogenic and nonvasculogenic erectile dysfunction (ED) and compare it with the control group. Mean PLT volume (MPV) levels were measured in 50 patients with vasculogenic ED, in 30 patients who developed ED after radical prostatectomy (nonvasculogenic) and in 40 healthy controls. Ages were similar between the three groups. The diagnosis of ED was based on detailed sexual history, physical examination, laboratory assessment and color Doppler ultrasonography and is defined as the inability to attain or maintain a penile erection that is sufficient for successful vaginal intercourse. The results are given as mean ± s.d. of the mean. The mean age of the patients with vasculogenic ED, of patients with ED after radical prostatectomy and of the control group were 53.70 ± 12.39 (range 24-77), 54.60 ± 11.40 (range 43-61) and 53.85 ±9.5 (range 30-73), respectively (P = 0.853). The MPV and PLT values were significantly higher in patients with vasculogenic ED than in patients with ED after radical prostatectomy and in control groups: 7.49 ± 1.4, 6.43 ± 1.19 and 6.85 ± 1.2 for MPV and 262.97 ± 68, 251.77 ± 78 and 252.89 ±82 for PLT values, respectively (P = 0.033). The MPV and PLT values were not statistically significant in postprostatectomy ED patients and in control groups (P = 0.663). There was no significant difference among the three groups in terms of white blood cells and hemoglobin levels. PLT count and mean PLT volume were detected to be increased in patients with vasculogenic ED. This finding may suggest a role for PLT volume in the pathogenesis of vasculogenic ED.