Epididymal fine needle aspirations (EFNA) were performed on 29 epididymides of 17 infertile, azoospermic men in whom testicular cytology revealed adequate spermatogenesis. Sonograms confirmed the presence of all the excretory male organs. EFNA was performed to diagnose and locate the site of genital tract occlusion. The presence of cuboidal epithelial cells in the aspirate was the sole indication that epididymal content was aspirated. In 10 (34%) of the 29 aspirates there were only cuboidal epithelial cells and no spermatozoa, indicating proximal occlusion in the rete testis, in the canaliculi efferents or in the most proximal segment of the epididymis itself. Occlusion in the distal segments of the epididymis or in the vas deferens was diagnosed in 13 epididymal aspirates (45%) which contained both cuboidal cells and spermatozoa. In 6 epididymides (21%) no conclusion could be reached because of failed aspirations. There are a variety of treatment modalities available for male genital tract obstruction, such as reconstructive surgery or IVF. The success rate of treatment is mainly dependent on the site of obstruction. Since vasography has its own limitations and hazards, diagnostic EFNA should be performed before treatment in men in whom genital obstruction is suspected.