A 2-month-old boy with delayed growth and development, brachycephaly, large anterior fontanelle, low-set folded ears, micrognathia, aortic coarctation, floppy abdominal muscles, and pes varus, was found to have a 46,XY,del(16)(q2100q2300) de novo karyotype. This observation corroborates both the distinctness of the 16q monosomy syndrome and the pathogenetic role of the band 16q21.