Background: There is a discrepancy between self-reported sexual identity and sexual behavior. The magnitude of this discrepancy is unclear, as is its variation across race/ethnicity and gender. Goal: The goal of the study was to assess the range of discrepancy in self-reported sexual identity and sexual behavior in men and women of four racial/ethnic groups. Study Design: Self-reported data on sexual identity (homosexual, bisexual, heterosexual) and sexual behavior in the past 3 months were collected from 1494 African American, Hispanic, Asian, and white men and women in public congregation places in Houston, Texas. Results: Data indicated that concordance rates between self-reported sexual identity and sexual behavior varied widely across racial/ ethnic groups, with the highest rates of concordance in Asian males and females and the lowest in African American females and white males. The largest discordant category was in those self-described heterosexuals who reported partners of both genders. Breakdown of data to exclude those who reported sex trade work or illegal sources of income improved the concordance rates for African American and Hispanic subsamples. Conclusion: Data indicate the importance of designing and targeting HIV risk interventions and clinical screening, based on behavior and not reported sexual identity.