Our objective was to examine associations between self-reported sexually transmitted infections (STIs) and sociodemographic, lifestyle, health status, health service use and quality of life factors among young Australian women; and their use of family planning and sexual health clinics and associations with health, demographic and psychosocial factors. The study sample comprised 14,762 women aged 18-23 years who participated in the mailed baseline survey for the Australian Longitudinal Study on Women's Health, conducted in 1996. The main outcome measures are self report of ever being diagnosed by a doctor with an STI, including chlamydia, genital herpes, genital warts or other STIs, and use of family planning and sexual health clinics. The self-reported incidence of STI was 1.7% for chlamydia, 1.1% genital herpes, 3.1% genital warts, and 2.1% other STIs. There was a large number of demographic, health behaviour, psychosocial and health service use factors significantly and independently associated with reports of having had each STI. Factors independently associated with use of family planning clinic included unemployment, current smoking, having had a Pap smear less than 2 years ago, not having ancillary health insurance, having consulted a hospital doctor and having higher stress and life events score. Factors independently associated with use of a sexual health clinic included younger age, lower occupation status, being a current or ex-smoker, being a binge drinker, having had a Pap smear, having consulted a hospital doctor, having poorer mental health and having higher life events score. This study reports interesting correlates of having an STI among young Australian women aged 18-23. The longitudinal nature of this study provides the opportunity to explore the long-term health and gynaecological outcomes of having STIs during young adulthood.