Objective: to compare transvaginal three-dimensional sonohysterography (3D SHSG) and diagnostic hysteroscopy with regrads to diagnostic accuracy , procedure time , and patient discomfort with a prospective randomized controlled cohort study in benha university hospitals. The study included a population group of 100 women with abnormal uterine bleeding .subjects with pregnancy, pelvic infection, large uterus ,suspicious or diagnosed pelvic malignancies, and who did not meet the criteria for day surgery ,were excluded. Materials and methods: patients were randomized into two groups :group 1 had hysteroscopy followed by SHSG while group 2 had SHSG followed by hysteroscopy.Diagnostic accuracy, patient discomfort of SHSG in comparison to hysteroscopy were studied, Results: A total of 100 patients completed the study. The average age of the study population was 32.8 years and the mean parity was 3. Nulliparas represented 9% of the study population and the average duration of symptoms was 14.8 months. Conclusion: Both hysteroscopy and SHSG are comparable in the diagnosis of intracavity lesions, pain rating, and procedure time. Three - dimensional SIS is an alternative to other invasive methods for diagnosing intrauterine pathology in AUB, and it was clear that 3DSIS has the ability to diagnose minor local uterine lesions that could be missed in other conventional imaging methods.