We describe a unique case of diagnosing salt-wasting congenital adrenal hyperplasia (CAH) caused by 21-hydroxylase deficiency in a 32-year-old male patient. Before establishing the diagnosis, the main patient complaint was infertility. In childhood, the patient suffered from developmental delay, often illness, overconsumption of salt, and often vomiting; he stopped growing at the age of 12 years. In the adolescent period, his physical condition improved. Later, the patient got married, but was infertile. Plasma steroid profiling by gas chromatography-mass spectrometry (GC-MS) revealed markedly increased levels of 17-hydroxyprogesterone and 21-deoxycortisol and a decreased cortisol level, which enabled the diagnosis of CAH and 21-hydroxylase deficiency. The diagnosis was confirmed by a molecular genetic study that detected a CYP21 gene mutation — l2 splice in the homo(hemi)zygotic state, which was characteristic of the salt-wasting form of CAH. Also, the patient had secondary adrenal cortical adenoma caused by prolonged ACTH hyperstimulation and secondary hypogonadism associated with excessive production of adrenal androgens, which led to elevated levels of estrogens inhibiting production of LH and FSH. Treatment of the patient with glucocorticoids and mineralocorticoids and then with androgens improved his clinical condition and hormonal parameters.