Infertility is the inability of a sexually active, non-contracepting couple to achieve spontaneous pregnancy in one year. Approximately 30% of all infertility cases are due to male infertility. But when treating a couple with fertility issue, we need to evaluate and treat both partners. Etiologically there are pretesticular, testicular and posttesticular causes of infertility. Pretesticular causes are related to hypothalamus – pituitary axis disturbance, resulting in insufficient testosteron production or abnormal spermatogenesis. The testicular causes are related to pathological changes in the testicle. Varicocele, cryptorhism, Klinefelter syndrome are the most common testicular reason for infertility. Posttesticular causes include conditions that interfere with sperm transport from the testicle to the urethra, and can be due to sperm motility malfunction, duct obstruction, disorders of ejaculation or due to erectile dysfunction. Diagnosis of infertility is based on anamnesis, clinical examination, hormonal status, semen analysis, radiological examinations, testicular biopsy. The semen analysis is the most important diagnostic parameter. The purpose of the infertility evaluation is to detect potentially reversible causes. Infertility treatment is based on surgical, non-surgical methods and assisted reproductive technology (IUI, IVF, ICSI). If assisted reproductive technology is insufficient, child adoption could be considered.