Prostate cancer (PCa) is the most common malignancy in men. Androgen deprivation therapy (ADT) is used in the treatment of locally advanced and metastatic PCa. Although its use has improved survival in a subset of patients, it also has negative consequences. Osteoporosis, sexual dysfunction, hot flashes and adverse changes in body composition are well-known and well-studied complications of ADT. Recent studies have also found metabolic complications in these men such as insulin resistance, diabetes and metabolic syndrome. In addition, these men might also experience higher cardiovascular mortality. Studies are needed to determine the mechanism behind these complications and to employ strategies to prevent them.