OBJECTIVE To determine the diagnostic value of hysterosalpingography (HSG) and diagnostic hysteroscopy in infertility evaluations. METHODS Comparative 2-year study. METHODS Outpatient infertility clinic of a tertiary medical center. METHODS Two hundred sixteen women being investigated for infertility. METHODS An HSG was followed by a diagnostic hysteroscopy. RESULTS The HSGs were interpreted as normal in 79 (36.9%) women and as showing some abnormalities of the uterine cavity in 135 (63.1%). In the former group, 51 patients had a normal uterine cavity, but 28 had abnormal findings on hysteroscopy, a false negative rate of 35.4%. Of 135 women with an abnormal HSG, hysteroscopy found a normal uterine cavity in 21, a false positive rate of 15.6%. The sensitivity of HSG was 80.3% in revealing intrauterine abnormality and its specificity was 70.1%. Although some abnormalities were identified by both methods in 114 women, findings of both procedures were similar in only 88 (77.2%). In 75 (35.0%), the findings of HSG differed from those of hysteroscopy. In only 139 (65%) patients were the findings (normal and abnormal) similar for both methods. CONCLUSIONS We advocate hysteroscopy in the investigation of female infertility for its accuracy, safety, simplicity, and convenience.