The concentration of chromium in the hair of thirty-three normal children and nineteen children with juvenileonset diabetes mellitus was measured by atomic absorption 8pectropholometry. The geometric mean for the group of normal children was 0.85 μg./gm.; range (mean ± 2 SD) 0.36 — 1.87 μg./gm., and for the diabetic children, 0.56 μg./gm. (range, 0.26 — 1.19 μg./gm.). Comparison of these results revealed a highly significant difference (p < 0.001) between the two groups.