The purpose of this study was to determine the age-specific rubella seroprevalence and factors associated with rubella seropositivity in unvaccinated adolescents in Ankara, Turkey. In this cross-sectional study 229 students were selected with stratified sampling methods in 2 primary and 2 high schools of low to medium socioeconomic status. Overall rubella seroprevalence was 92.6%. There was a significant association of rubella seropositivity with age and history of exanthema disease. Recommendations are made for vaccination of all children at age 1 year, combined with a one-time campaign of vaccination of adolescent girls and young women to provide future protection for those who are about to enter the child-bearing age.