A group of transsexuals, 9 biological men and 10 women, was assessed according to clinical DSM-III-R diagnosis and a self-report instrument for Axis II diagnoses based on the Structured Clinical Interview for DSM-III-R (SCID screen). A control group of 133 individuals was assessed by the same instrument. Combined with a functional criterion according to the Global Assessment of Functioning, the SCID screen showed good agreement with clinical Axis II diagnoses. The overall proportion of Axis II criteria fulfilled, proportion of criteria fulfilled for every single personality disorder and number of personality disorders were calculated from the modified version of the SCID screen. Personality disorders, mainly within cluster B, were identified among 5 of 19 transsexuals, and a majority had multiple personality disorders. Among controls, no personality disorder was identified. Personality traits as measured by the SCID screen revealed significantly more subthreshold pathology among transsexuals than controls in 8 of 12 personality categories. The proportion of overall Axis II criteria fulfilled was 29% among transsexuals versus 17% among controls. Sex differences among transsexuals, the usefulness of the SCID screen and diagnostic problems in DSM-III-R with respect to gender identity disorders are discussed.