Hot flashes are as common in men who have been castrated due to prostate cancer as hot flashes are in women after menopause. The symptom can cause significant discomfort for a considerable length of time. The hot flashes are most likely caused by a reduction in sex-hormone levels, which, in turn, causes an instability in the hypothalamic thermoregulatory center. Calcitonin gene-related peptide is involved in menopausal hot flashes in women and possibly also in castrated men. The mainstays of treatment for castrated men with hot flashes remain estrogens, progesterone, and cyproterone acetate, each of which has different side effects. Other treatments for hot flashes include clonidine and antidepressants and, according to one uncontrolled study, electrostimulated acupuncture. Nonetheless, there is a need for more effective and less toxic treatments. In this review, we will discuss the prevalence, duration, distress, physiology, and treatment options of hot flashes in men subjected to castration therapy due to prostate cancer.