The diagnostic usefulness of the radionuclide hysterosalpingography (RN-HSG) .was evaluated after a year of its use in 39 female patients who underwent basic diagnostic tests (endometrial biopsy, post coital test) for infertility.The results of the radionuclide evaluation were compared with classic hysterosalpingography (37/39 patients) and laparoscopy (32/39 patients). In 32 patients all three procedures were performed. When using the basic diagnostic tests and classic hysterosalpingography, 12 patients, or using the laparoscopy, 16 patients were entirely normal. Of these 8/12 (66%) and 12/16 (75%) were obstructed at RN-HSG. When using both techniques (classic hysterosalpingography and laparoscopy) 10 patients were normal. Of these 6/10 (60%) were obstructed at RN-HSG.According to these results (66%, 75% and 60%), it was possible to identify the reason for the infertility and to decide on the therapy of these 6 patients with an unknown reason of infertility. In this kind of patients it was suggested that infertility was due to an impaired tubal transportation capacity.