Abstract Purpose To evaluate the prevalence and the behavioral and historical determinants of genital chlamydial infection among adolescent females in Hungary. Methods A total of 214 consecutive, unselected, self-referred, sexually active, nonpregnant female individuals aged 16–20 years were evaluated by polymerase chain reaction through the use of questionnaires. Results The prevalence of chlamydial infection within this population was 7.9%. We find that the most important correlates of chlamydial infection were at least three lifetime sexual partners ( p < .005), two or more sexual partners in the preceding 3 months ( p < .05), and symptoms of vaginitis ( p = .002). Conclusions The high prevalence of chlamydia in this study population may justify universal testing in Hungary.