The prenatal diagnosis of skeletal dysplasias is often initiated by the finding of a shortened extremity during a routine sonographic examination. Second-trimester diagnosis of these anomalies allows the couple to consider the option of terminating a pregnancy when a lethal anomaly is detected. A 21-year-old Bedouin woman underwent routine ultrasonographic screening at 20 weeks' gestation. Severe micromelia, a narrow thorax with shortened ribs, and postaxial polydactyly were detected. The patient delivered a male dwarf at 20 weeks' gestation following prostaglandin induction of labour for a diagnosis of short-rib polydactyly syndrome type III. The prenatal ultrasonographic diagnosis of short-rib polydactyly syndrome type III was made at 20 weeks' gestation, allowing termination of the pregnancy. A proper sonographic approach to skeletal dysplasias allows both early detection and differentiation between lethal and non-lethal anomalies.