77 venographic studies of impalpable testes have been reviewed. All patients subsequently underwent surgical exploration. In 28 studies a pampiniform plexus was identified and in 27 a testis was present at the site of the pampiniform plexus. In 20 studies the testicular vein was blind-ending and in only 1 was testicular tissue present at the site of the blind-ending vein. Testicular tissue was absent in the remaining 19. There were 29 technical failures or an inability to identify the full length of the testicular vein because of patent valves. Testicular venography is most useful in localising the position of an impalpable testis but does not determine in all cases whether testicular tissue is present.