De novo interstitial 16q deletion diagnosed in utero has not previously been reported. We present a case of fetal de novo interstitial 16q deletion associated with the sonographic findings of prominent coronal sutures, a prominent frontal bone, and shortening of the long bones. Genetic amniocentesis at 23 weeks' gestation revealed a de novo deletion of 16q13-q22. At birth, the fetus manifested a dysmorphic phenotype correlated with monosomy 16q syndrome. Linkage analysis of the family confirmed the maternal origin and the extent of the deletion. We suggest that prenatal detection of a prominent frontal bone with prominent cranial sutures and shortening of the long bones should prompt cytogenetic analysis looking for a deletion in the long arm of chromosome 16.