BACKGROUND: Noninvasive molecular tests for bacterial sexually transmitted infections (STIs) provide new opportunities for testing in nonclinical settings. Little information is available on the outcomes when applied to asymptomatic sex survey participants. OBJECTIVE: The objective of this study was to examine patient treatment preferences and partner notification outcomes among Chlamydia trachomatis-positive cases identified in the 2000 national survey of sexual attitudes and lifestyles (Natsal 2000), and factors associated with providing a urine sample. METHODS: The authors conducted a stratified probability sample survey of 11,161 men and women aged 16 to 44 years residing in Britain using computer-assisted self-interviews. Urine testing was performed for C. trachomatis offered to a random half of sexually active respondents aged 18 to 44 using ligase chain reaction. Notification, treatment, and follow up of ligase chain reaction-positive respondents were undertaken. RESULTS: A total of 5105 respondents were invited to provide a urine sample. A total of 3628 (71%) agreed and 3608 samples were successfully tested. Willingness to provide a urine sample was significantly higher among those reporting previous homosexual experience, heterosexual anal sex, and STI diagnosis. Seventy-three respondents (31 men and 42 women) were diagnosed with genital chlamydial infection. Sixty-five (89%) responded to notification of their infection and were recommended for treatment and partner notification. Fifty (77%) respondents preferred to be seen by their general practitioner and 15 (23%) by their local genitourinary medicine clinic. Although physician feedback on treatment and partner notification outcomes was obtained for only half (n = 34) of respondents, follow-up respondent interviews confirmed that a total of 49 (75%) respondents underwent this process. INTERPRETATION: In this community-based survey, the rate of provision of urine samples was high, and those who provided samples were found to be at somewhat greater risk of infection on average. This was accounted for in estimating population chlamydia prevalence. The authors found that treatment and partner notification of newly diagnosed infections can be successfully achieved in STI prevalence studies.