Quantitative analysis of digitopalmar ridge count was performed in forty male patients with rheumatoid arthritis to evaluation of genetic factors in that disease. Twenty five variables (ridge count on each of ten fingers, their sum on five and ten fingers, four traits on each palm, i. e. ridge count between a-b, b-c and c-d triradii, their sum on each and both palm and at angle on two palms and their bilateral sum) were determined. The data thus obtained were compared with digitopalmar prints of 200 healthy men who served as a control group. A significant difference from the control group was found in eight variables. Ridge count was increased on the first and fifth finger bilaterally, on the fourth right finger tip, and their sum on each, and both fists. Accordingly, a polygenic system identical in some loci to the polygenic system predisposing to rheumatoid arthritis susceptibility might be found responsible for the dermatoglyphic pattern development. That means that they could used, and that is the aim of this study, as a diagnostic tool in rheumatic diseases.