Deletion of a portion of the short arm of chromosome 7 is associated with a recognizable phenotype which often includes craniosynostosis. Recent reports have suggested that craniosynostosis occurs only if there is a deletion involving band 7p21 or the segment distal to that band. We report on a boy who had an interstitial deletion of 7p, not involving band 7p21 or the segment distal to that band, who nevertheless had craniosynostosis. Thus, it appears that the determination of craniosynostosis in this syndrome is more complicated than has been suggested previously.