The ultrasonographic evidence of an irregular mixed mass, cystic and solid, in retrouterine area and the high levels of alpha(1)-FP values in a young pregnant woman, indicated the possibility of an ovarian germ cell neoplasia. Respecting the patient's will, pregnancy was protracted until the 36th week. A cesarian section allowed the releasing of a vital fetus and the removal of a neoplastic mass which proved to be an endodermal sinus tumor (EST) at stage Ia. Then the patient, the 12th case of EST in pregnancy reported in the literature, underwent 5 PVB chemotherapy cycles and, 3 years after the intervention, appears disease-free.