The immediate adverse effects of androgen deprivation therapy (ADT) in the treatment of prostate cancer (PC) are loss of secondary male sexual characteristics, erectile dysfunction (ED), including vasomotor hot flushes, loss of libido, fatigue, gynecomastia, anemia, and osteoporosis. ADT also cause complex little-studied male metabolic changes, such as reduced muscle mass and increased gynoid fat mass. It also decreases insulin sensitivity and high-density lipoprotein cholesterol (HDL-C) and increases low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG). In accordance with these adverse metabolic effects, ADT may be associated with the higher rate of type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD). Whether ADT gives rise to T2DM and cardiovascular events is still unknown since the evidence is contradictory. However, the metabolic processes during ADT have significant differences from the classical metabolic syndrome (MS). The review describes the existing problems in the investigation of biochemical processes resulting from androgen deprivation in PC. The paper considers recently described metabolic complications caused by ADT, which include obesity, insulin resistance, and lipid changes, as well as the association of ADT with T2DM and CVD during different hormone therapy regimens. Since practically all investigations enrolled heterogeneous groups of patients who had varying extent of PC and those from different prognostic groups of progression, as well as different ultimate objectives and different therapy regimens; the final interpretation of results is extremely difficult. Further investigations in this field, by applying the standardized criteria are called.