Objective:This comparative study was designed to assess the role of saline infusion hysterosonography in refining the diagnosis of uterine cavity abnormalities diagnosed by hysteroscopy in infertile, asymptomatic women beforein vitro fertilization/intra-cytoplasmic sperm injection (IVF/ICSI) treatment.Methods:One hundred and twenty four asymptomatic infertile women were included in this study before IVF/ICSI treatment. Hysteroscopy was done as routine procedure for uterine cavity assessment before the first attempt of IVF/ICSI treatment. Patients agreed to have an ultrasound assessment of uterine cavity with the use of saline as the contrast medium (Saline infusion hysterosonography, SIHS) beside the hysteroscopic assessment. Both hysteroscopy & SIHS procedures were scheduled post menstrual period in the early-mid follicular phase of a cycle of the same menstrual cycle, 1-3 months before starting the IVF/ICSI treatment.Results:The uterine cavity abnormalities were detected in 40.3% of the patients included in this study before IVF/ICSI treatment (17.7% endometrial polyps, 10.5% sub-mucous fibroid, 4.8% uterine septum, 3.2% uterine adhesions, 2.4% endometrial hyperplasia and 1.6% thin or atrophic endometrium). In this study, the hysteroscopy was more sensitive (98.0% versus 96.2%), more specific (100.0% versus 98.7%) and more accurate (99.2% versus 97.6%) than SIHS, and the hysteroscopy also had higher predictive values (100% versus 98% positive predictive value; 98.7% versus 97.4% negative predictive value) than SIHS during uterine cavity assessment before IVF/ICSI treatment.Conclusions: Infertile asymptomatic women should be screened for possible uterine cavity abnormalities before IVF/ICSI; SIHS is a simple, well tolerated procedure that can be used as a complementary tool to confirm the diagnosis of uterine cavity abnormalities detected by hysteroscopy.