Digital and palmar dermatoglyphic patterns of 155 children with cryptorchidy has been studied. Results were compared to two control groups of Spanish normal population. 50 and 300 males respectively, showing the following statistically significant differences: 1. High incidence of whorls (37.4% vs. 22.2% and 29.5%) and low frequency of ulnar loops (51.5 vs. 66.4 0 and 60.8%) on fingers. 2. Frequent recurrence of some digital patterns, with a higher frequency of accumulated whorls and lower frequency of accumulated ulnar loops. 3. Increased amplitude of atd angle. 4. No differences in finger ridge count or ab ridge count.