Hand and palm dermatoglyphics were studied in 158 insulin-dependent diabetic children and adolescents [85 with limited joint mobility (LJM) and 73 without]. The findings in this group were compared with those in 400 control subjects, with a similar racial distribution. The main dermatoglyphics alterations found in diabetic patients with LJM, as compared with non-LJM diabetic patients and controls, may be summarized as follows: (a) decrease in digital total ridges count (TRC); (b) higher frequency in the number of arches; (c) decrease in the sum of a line and cubital loops, particularly in the women; (d) increase in the number of t'-axial triradii. These alterations suggest a genetic aetiology of this complication. Further studies are recommended in order to provide more insight into the origin of this disorder.