Office hysteroscopy and hydrosonography have long been viewed as competitive methods. This study was aimed to find out whether a combined approach of hysteroscopy followed by hydrosonography could provide more accurate information about the uterine lumen. Consecutive patients referred for diagnostic hysteroscopy were recruited to the study. Each patient had a transvaginal ultrasound scan, hysteroscopy, and immediately thereafter hydrosonography. Additional information retrieved by hydrosonography was recorded. When hysteroscopy revealed a normal uterine cavity, no further information was gained from hydrosonography. However, in 80% of the cases where hysteroscopy showed an abnormal uterine cavity (e.g., septum, adhesions, fibroid, endometrial polyp), hydrosonography added significant information regarding the size of the lesion, degree of fibroid encroachment, or luminal contour. We conclude that a combination of diagnostic hysteroscopy and hydrosonography could serve as a simple "one-stop" approach for full evaluation of the uterine cavity.