The present study of a correlation between stature of male psychiatric patients and character disorder as well as criminality has been made on the background of the findings of such a correlation in persons with the XYY syndrome by Jacobs et al. (1965), Casey et al (1966), Price et al. (1966 and 1967), Welch et al. (1967), Bardett et al. (1968), Court Brown et al (1968), Hunter (1968), Nielsen (1968) and Wiener et al. (1968), and to a certain extent also in persons with a large Y chromosome (Nielsen, 1968). These findings indicate that males with two Y chromosomes, and probably also males with a large Y chromosome, have a higher disposition to tall stature, character disorder and criminality than is found in the general male population. There might be a Y-linked inheritance of tall stature, character disorder and criminality irrespective of the size of the Y chromosome. If these hypotheses are true, one would expect to find a higher frequency of patients with character disorder and criminality among males with a stature above 181 cm. compared with males below 181 cm., and the present study has been made in order to compare the frequency of character disorder and criminality in psychiatric patients in these two stature groups.