We report on an infant boy with duplication of part of 16p and partial deficiency of 9p: 46,XY, -9, + der(9)t(9;16)(p24;p13.1)mat. The child has the typical phenotype of dup(16p) even though the extra piece of 16p is small (16p13.1----pter). Manifestations include severe developmental delay, rounded face, sparse hair, ear anomalies, hypertelorism, cleft soft palate, a thin vermilion border of the upper lip, and left renal dysgenesis. We review 16p duplications.