Finger prints and sex - chromatin were investigated in a random nrelated 150 males (age range; 18-40) were divided to three samples (each sample consist of 50 unrelated males), the sexual – offenders (sample A), the murderers (sample B) both from correctional institutions of the adults in Baghdad and control (sample C)j,and these finger prints were analyzed qualitatively and quantitatively. The qualitative analysis revealed significantly increased frequencies of whorls and arches and decreased of loops (radial and ulnar) when comparisons were made between samples A and C, (XX2 = 8.357, D. F. = 3, P < 0.05), but when sample B compared with C or A samples,: no any significant differences was observed. With respect to the pattern intensity index, there was an increasing in its value when sample A was compared to the samples B and C. This increasing may be attributed to the forthcoming increased frequency of whorls in this sample. In the quantitative analysis, no significant differences were observed in the student "t" test when comparisons were made between the three studied samples (A, B and C), in means of digital counts. When the total ridge count (T. R. C) and absolute ridge count (A. C.) were considered, decreased means were observed in sample A in comparison with sample B and C. However, these deviations did not reach a significant level. The variance of T. R. C. and A. R. C also decreased in sample A when compared with samples B and C. Bimanual comparison have been made. The frequency T, R. C. in three studied samples were analyzed by determining their skewness and kurtosis, the values of latter was negative which might indicates a flattening of distribution curve in all the studied samples. With respect to the correlation coefficient (r), which occurred mainly between homologous and adjacent fingers, the unilateral analysis showed (17) significant differences between samples A and C, while (13) significant differences between samples B and C, and (9) significant differences between samples A and B. In bilateral analysis (7), (4) and (7) significant differences during the comparison between the samples A and C, B and C, and A and B, respectively In the examination of sex - chromatin in the individuals of the three studied samples (A, B and C), only two sexual - offenders (in sample A) are positive sex - chromatin which was indicated the presence of an additional X - chromosome (sex - chromosome (s) abnormality), h. therefore T. R. C., were decreased in this sample when was compared with samples B and C. Finally and through the relationship between sex - chromatin ^ existence and dermatoglyphic differences, we can conclude that, the most of sexual deviations cases can be affected by the biological structure.(genetics) with the aid of environmental factors, while no any effect of genetics on the murdering criminals (in sample B).