Immunological, endocrinological, and haematological abnormalities are relatively common in people with Down syndrome (Cuadrado & Barrena, 1996; Decoq & Vincker, 1995; Hestnes et al., 1991; Sustrova & Strbak, 1994; Nespoli, Burgio, Ugazio & Maccario, 1993; Kempski, Chessells & Reeves, 1997; Kivivuori, Rajantie, & Siimes, 1996; David et al., 1996; Gjertson, Sturm & Berger, 1999). Zinc is one of the elements that act in the maintenance of normal function of these systems. This study was designed to investigate zinc levels in children with Down syndrome. Zinc levels were measured in hair using atomic absorption spectrophotometry. The hair zinc level of 19 children with Down syndrome was compared with the zinc level of 11 typically developing children. Hair zinc levels were found to be significantly lower (p less than 0.05) in those with Down syndrome (average 95.18 [plus or minus] 56.10 ppm) than in the typically developing children (average 208.88 [plus or minus] 152.37 ppm). Some of the problems experienced by children with Down syndrome may be due to these low zinc levels, but further research is required to confirm these results, and to establish any correlation with these problems. (Contains 2 tables.)