Background: Hysteroscopy has revolutionized the field of Gynecology and the management of many gynecological conditions. It has now become a standard part in the diagnosis of postmenopausal bleeding by the gynecological surgeons. Cost, convenience, accuracy, and patient acceptability of these procedures are clearly superior to those of traditional surgeries. As gynecologists have grown better acquainted with the benefits and techniques of operative hysteroscopy, it has become the method of choice for treatment of intrauterine pathology. Cervical ripening is a complicated process, being mediated by cytokines, growth factors, hormones and other biochemical compounds. Both dinoglandin and Misoprostol can be used for cervical ripening before introduction of hysteroscopy and hence reduce the incidence of complications. Objects: This study aims to assess the efficacy of dinoprostone compared to misoprostol in cervical ripening in nulliparous women undergoing diagnostic hysteroscopy. Methodology: a randomized controlled clinical trial comparing dinoprostone versus misoprostol for cervical ripening before diagnostic hysteroscopy in nulliparous women, it included 2 groups, 33 patients each. In the first group named (group D) dinoprostone 3 mg was applied vaginally 6 hours before diagnostic hysteroscopic procedure while in the second group named (group M) 400 mcg misoprostol was applied vaginally at the same timing. Results: There was no statistically significant difference between the groups that received misoprostol or dinoprostone with regard to age, duration of marriage, medical disorder, history of gynecological operations and type of gynecological operations. However, the use of misoprostol caused slightly less pain compared to dinoprostone but more side effects occurred with the use of misoprostol. Conclusion: There was no significant difference between dinoprostone and misoprostol in priming of cervix before diagnostic hysteroscopy in nulliparous women regarding ease of hysteroscope entry, pain or side effects.