Standard diagnostic laparoscopy is considered the gold standard to investigate tubo-peritoneal infertility. It requires general anaesthesia and full operative facilities. Due to the risk of complications, laparoscopy is frequently postponed to the final stage of infertility evaluation or even after treatment trials have failed. Transvaginal hydrolaparoscopy (THL) is based on vaginal access using a needle puncture technique and saline for distention. THL can be performed on an outpatient basis under local anaesthesia. However, little data exist concerning the accuracy of THL in comparison with laparoscopy. We conducted a prospective comparative blind trial to assess the feasibility and accuracy of THL compared with diagnostic laparoscopy in infertile women. Sixty women were assigned to undergo THL immediately prior to laparoscopy. Different operators evaluated the findings of the two procedures. In order to evaluate the accuracy of THL, findings in terms of tubal pathology, endometriosis and adhesions were analysed. The success rate of accessing the pouch of Douglas was 90.2%. Complication rate was 1.6%. THL diagnosis was correlated with that of laparoscopy in 92.3% of cases. In cases of abnormal findings by THL, there were no normal laparoscopies. Our pilot study suggests that THL is a safe and reproducible method. Retroverted uterus should be considered as a relative contraindication to THL. When a complete evaluation by THL is available, it is a highly accurate technique in comparison with the laparoscopy.