A prospective study was undertaken to evaluate the efficacy of radionuclide hysterosalpingography (RN-HSG) using Tc-99m-labeled human albumin microspheres to assess the patency of the fallopian tubes in 36 women (72 tubes). The study group consisted of 20 women with proven fertility undergoing laparoscopic tubal ligation, 8 with male factor infertility and 8 with bilateral isthmic tubal occlusion. All RN-HSG scan results were correlated with the findings at laparoscopy when tubal patency was ultimately assessed with chromopertubation. The sensitivity and specificity of RN-HSG were 100% and 94.6%, respectively. The positive predictive value (probability of occlusion when RN-HSG was positive) was 84%, whereas the negative predictive value (probability of no occlusion when RN-HSG was negative) was 100%. RN-HSG is a simple and potentially useful method of assessing the patency of the fallopian tubes.