Although most cases of male infertility are the result of primary testicular abnormalities (either maturation arrest, decreased spermatogenesis, or germinal hypoplasia), obstruction of the genital tract is a well recognized and potentially correctable cause of infertility. Seminal vesiculography is an excellent method of evaluating the male genital tract not only for obstruction but also for other structural lesions that may cause infertility. In 27 patients undergoing vesiculography as part of an evaluation of infertility, obstruction was found in 25%. Three patients (11%) were found to have nonobstructing structural lesions as a possible cause of infertility. Patients with obstructive lesions were found to have significantly lower semen volumes than those with patent outflow tracts. The continued role of seminal vesiculography in the evaluation of male infertility is discussed.