A fetus at 24 weeks of gestation had been suspected of congenital familial bilateral short femur. The Japanese mother, 41 years old and 139 cm in height presented with bilateral short femur herself. The mother had two affected aunts and one affected daughter in her family history. Ultrasound examination was given to the mother for the first time at 24 weeks of gestation and it revealed bilateral short femur of 30 mm in length on the right and 31 mm on the left femur of the fetus. Other examinations were entirely normal and the pregnancy resulted in a full-term spontaneous vaginal delivery to a male baby. Birth weight was 2,790 g and the 1 and 5 min Apgar scores were at 8 and 10. Diagnosis was confirmed by skeletal radiographs.