We report a 3-year-old girl with fetal hydantoin syndrome (FHS) whose mother had received phenytoin 600 mg/day throughout gestation. She had growth retardation, mental deficiency, craniofacial dysmorphism and iris colomobata specific to FHS. However, the patient did not have the distal phalangeal hypoplasia which is associated with FHS; instead, she had polydactyly of the right foot. This seems to be the first FHS case in the literature with polydactyly.