['To evaluate and compare the accuracy of transvaginal sonography (TVS) and sonohysterography (SHG) in the investigation of women of reproductive age presenting with irregular uterine bleeding (IUB).', 'This prospective study included 104 women presenting with IUB. All patients underwent TVS, SHG, and hysteroscopy, during which endometrial biopsies were obtained and any endometrial mass was treated with hysteroscopic surgery. Statistical analysis was performed by calculating the sensitivity, specificity, and positive and negative predictive values of TVS and SHG in diagnosing endometrial polyp, submucous myoma and all endometrial pathologies (polyp, submucous myoma, endometrial hyperplasia, and endometrial carcinoma) with the histopathological report of the tissues obtained by hysteroscopy serving as the end point for the analysis.', 'The sensitivity, specificity, and positive and negative predictive values, respectively of TVS were 61.2%, 90.9%, 85.7%, and 72.5% for diagnosing endometrial polyps; 75.0%, 92.0%, 63.1%, and 95.3% for diagnosing submucous myomas; and 75.0%, 80.6%, 87.9%, and 63.0% for diagnosing any kind of pathology. The corresponding diagnostic values of SHG were 83.7%, 96.4%, 95.3%, and 86.9% for polyps; 87.5%, 98.9%, 93.3%, and 97.8% for submucous myomas; and 88.2%, 91.7%, 95.2%, and 80.5% for any kind of pathology.'] Is sonohysterography superior to transvaginal sonography for the diagnostic approach of irregular uterine bleeding in women of reproductive age?