We describe our experience in diagnosing prenatal-onset achondrogenesis type II by a multidisciplinary assessment.<h4>Methods</h4>Two cases of fetal achondrogenesis type II were analyzed retrospectively using prenatal ultrasound evaluation, postnatal radiographic diagnosis, and molecular genetic testing of <i>COL2A1</i>.<h4>Results</h4>A causative mutation in the <i>COL2A1</i> gene was found in both patients. This evidence concerns the gene COL2A1 and achondrogenesis type II.