Male infertility is a complicated and often poorly understood patholog
ic process. The cause of a man's infertility frequently remains unknow
n even after a thorough evaluation. Many of the currently available me
dical therapeutic options are empirical and lack documentation of effi
cacy. New diagnostic tests are emerging that may help define some prev
iously obscure causes of infertility. Only when these abnormalities ha
ve been clearly identified will more specific and cost-effective treat
ment regimens be instituted.