Objective This study examined the associations between current behaviours/characteristics and self-perceived risk for STIs, among randomly selected women aged 18–45 years from Denmark, Norway and Sweden.

Method A population-based, cross-sectional, questionnaire study (paper based, web based and telephone based) was conducted during 2011–2012. We compared medium–high STI risk perception with no/low risk perception. The associations were explored for women who had ever had sexual intercourse and for women with a new partner in the last 6 months using multivariable logistic regression.

Result The overall prevalence of medium–high STI risk perception was 7.4%. It was highest among women aged 18–24 years (16.2%) and among the Danish women (8.8%). Number of new sexual partners in the last 6 months (≥3vs 0 partners, OR 14.94, 95% CI 13.20 to 16.94) was strongly associated with medium–high STI risk perception. Among women with a new partner in the last 6 months, lack of condom use increased medium–high STI risk perception (OR 1.73, 95% CI 1.52 to 1.96). Genital warts in the last year, binge drinking and being single were associated with increased risk perception and remained statistically significant after additional adjustments were made for number of new partners and condom use with new partners in the last 6 months.

Conclusion Subjective perception of risk for STI was associated with women’s current risk-taking behaviours, indicating women generally are able to assess their risks for STIs. However, a considerable proportion of women with multiple new partners in the last 6 months and no condom use still considered themselves at no/low risk for STI.