Neuroendocrine neoplasms (NENs) of the genitourinary tract are uncommon, but the pathologist has to be prepared to recognize them and to assess the morphophenotypic factors that can drive their treatment and prognosis. NENs have been described in the kidney, urinary bladder, prostate, testes, uterine cervix, uterine corpus, and ovaries. The clinico-pathological features and the nomenclature of these neoplasms may vary from site to site. This chapter systematically reviews the spectrum of genitourinary NEN within the context of a unitary vision of the diagnostic criteria and classification, paralleling the scheme recently proposed by the World Health Organization and the International Agency for Research on Cancer (IARC).