Introduction: Emergency contraceptive pill (ECP) use is reported to have increased in several countries over time. In this multi-country population-based questionnaire study, we aimed to describe the patterns of ECP use and identify factors associated with its use. Material and methods: In 2011-2012, women aged 18-45 years were randomly selected from national registers in Denmark, Norway and Sweden and invited to respond to questions related to lifestyle and contraceptive use. We used generalized logistic models to estimate odds ratios (ORs) and 95% confidence intervals (CI) comparing women who had used ECP with women who had never used ECP. Results: Of the 45 445 women, 33.9% (Denmark = 32.3%, Norway = 35.1%, Sweden = 34.6%) had used ECP at least once in their lifetime. Among ECP users, 15.8% had used ECP within the last year and 50.0% had used ECP more than once in their life. After adjusting for country, age at response and response type, ECP use was associated with higher education (OR 2.09, 95% CI 1.54-2.84) and being single, divorced or widowed (OR 3.17, 95% CI 2.87-3.49). Binge drinking and smoking increased the odds of ECP use. Furthermore, early age at first intercourse (OR 1.29, 95% CI 1.08-1.55), having a new partner in the last 6 months (≥3 partners: OR 6.44, 95% CI 5.46-7.60) and lack of condom use with a recent new partner (OR 1.42, 95% CI 1.22-1.66) were found to be associated with ECP use. Conclusions: Our study shows that ECP use is common among Scandinavian women. Higher education and being single were associated with increased odds of ECP use. Risk behaviors such as smoking and early age at first sex were also associated with increased odds of ECP use. Since ECP use is not protective against sexually transmitted infections, our findings highlight the need to encourage awareness and regular use of condoms to prevent sexually transmitted diseases in women.