We report on a 26-year-old male with profound psychomotor retardation and a pattern of dysmorphic features and malformations characteristic for duplication of the short arm of chromosome 16. He has an elongated face, sparse hair, upslanting palpebral fissures, anteverted nostrils, hypoplastic thumbs on both hands, and dislocation of several joints. His chromosome aberration was diagnosed at birth and was due to an unbalanced segregation of a maternal translocation t(2;16)(q36;p11). At 26 years of age he is, to the best of our knowledge, the oldest patient with duplication of 16p reported to date. We present a long-term observation of growth, psychomotor development, dysmorphic features and evolution of his skeletal and joint defects as well as a review of the literature. © 2007 Wiley-Liss, Inc.