Azoospermia is the absence of sperm cells in the ejaculate, also in the sediment after spinning. It is a key reason of male infertility. In terms of reasons, diagnostics and treatment methods obstructive azoospermia (40%) and nonobstructive azoospermia (60%) are recognized. The operative treatment of obstructive azoospermia gives a big chance of pregnancy, but if it is non efficient the sperm cells are aspirated from epididymis or testis for in vitro fertilization. The hormonal treatment in nonobstructive azoospermia is often ineffective, but the only chance to have biologically own offspring may be sperm retrieval for in vitro fertilization. Hopefully new genetic tests can help in preconceptional diagnostics of male infertility and in assessment of inheritance of these abnormalities in offspring.