Since testes and adrenal cortex derive from the same urogenital ridge, adrenal tissue with descending gonads may migrate in early embryonic period. Although most often ectopic tissue undergoes atrophy, in some cases, when adrenocorticotrophic (ACTH) overstimulation occurs, the adrenal remnants in the testes may become hypertrophic and form testicular adrenal rest tumors (TARTs). The growth of TARTs in the testes leads to obstruction of the seminiferous tubules which can mechanically impair the function of the gonads and cause irreversible azoospermia. We describe a patient suffering since neonatal period from congenital adrenal hyperplasia (CAH), disorder with defected pathway of cortisol production, which leads to increased ACTH production and to overstimulation of adrenal cortex. He had very poor disease control and therefore in late puberty he was diagnosed with TARTs. At the age of 19.5 he was diagnosed with azoospermia, most likely caused by TARTs. It is the first evidence of TARTs in Polish literature. Although not many cases have been published so far, the incidence of TARTs seems to be highly underdiagnosed, so it seems reasonable to consider the disease in differential diagnosis of male infertility.