Twenty cases of nonimmunologic hydrops fetalis were reviewed. The incidence of nonimmunologic hydrops fetalis was 1/2,029 (20 cases in 40,588 deliveries). The diverse etiologies of nonimmunologic hydrops fetalis are demonstrated. The incidence of erythroblastosis fetalis caused by Rh isoimmunization declined markedly. The perinatal mortality rate was 14/18 or 78%. Prematurity, the presence of congenital anomalies, and the severity of hydrops fetalis contribute to this poor prognosis. However, a better understanding of the pathophysiology of hydrops fetalis, along with early detection by ultrasonography, preterm delivery with the liberal use of cesarean section, and availability of high-risk perinatal units, may enable us to improve the prognosis. A precise diagnosis should be attempted by careful antenatal and postnatal evaluation, so that accurate genetic counseling can be offered.