The aims of this study were to develop a sexual orientation attitude scale and use it to investigate the attitudes of psychiatrists, other physicians and first year medical students toward homosexuals and homosexuality in Ankara, Turkey. A cross-sectional study was performed with three groups including psychiatrists (n = 147), non-psychiatric physicians (n = 224) and first year medical students (n = 280). A scale with 43 items consisting of four subscales (heterosexism, homophobia, homonegativity, neutrality) was developed which showed high internal consistency, validity and reliability in this sample of Turkish individuals. The internal consistency coefficients (Cronbach's alpha) for the subscales were 0.85-0.86, 0.95-0.95, 0.95-0.95, and 0.85-0.86, respectively. Being male, single, a graduate of a religious (Imam Hatip) or vocational high school, of rural origin, a student, more religious, heterosexual and studying at university hospitals were found to be related to higher scores (indicating more negative attitudes) on all subscales and the total scale and these differences were significant. Students had the highest scores and psychiatrists had the lowest scores in all subscales and the total scale. The results of this study indicate that physicians and medical students have negative attitudes toward homosexuals and that medical training on sexual health issues should be improved in Turkey.