Objective: This prospective study investigated the prevalence of adenomyosis in histopathological examinations of patients who had undergone hysterectomy due to various indications in our clinic. Epidemiological characteristics, predisposing risk factors, symptoms and clinical findings of adenomyosis were evaluated Method: A total of 298 subjects who had undergone abdominal, vaginal or laparoscopic hysterectomy with/without salpingooophorectomy between October 2003 and April 2004 in our clinic were included. Uterine specimens obtained through hysterectomy were weighed and histopathologically examined in the Pathology Department of Ege University. The study group (n = 103), cases with adenomyosis, was compared with the control group (n = 195), cases without adenomyosis, with respect to the epidemiological, clinical and histopathological characteristics. Results: The prevalence of adenomyosis in 298 subjects was 36.2% (I 03). Duration of the reproductive period in patients with adenomyosis was found to be significantly longer than for those in the control group (p < 0.05). Prevalence of pelvic pain, dysmenorrhea and dyspareunia was also significantly higher in the study group (p < 0.05). Moreover, the number of cases requiring blood transfusion before the operation was significantly higher in the study group (p < 0.05) as were the rates of smoking, previous uterine surgery and nulliparity (p < 0.05). The most common gynecological condition accompanying adenomyosis was found to be uterine myoma in both groups, but the difference was not significant. Conclusion: Adenomyosis is not a rare histopathological finding. Due to diagnostic and therapeutic methods which are being developed as an alternative to hysterectomy, the clinical effects of adenomyosis and its association with other gynecological conditions, adenomyosis appears to be an issue which will be more intensively investigated in the future.