AIMS: The aim of the study was to investigate physical activity prior to pregnancy, occupation, and treatment in women with low back pain and pelvic pain (LBPP) during pregnancy. METHODS: All women who gave birth at two hospitals in northern Sweden from 1 January 2002 to 30 April 2002 were invited to complete a questionnaire on their obstetric and gynaecological history, actual pregnancy, and delivery. The sample was analysed with calculation of odds ratios (OR) and their 95% confidence intervals (CI). Cox regression analyses were performed. Women with LBPP reporting a pain maximum of 7 or more on a visual analogue scale (0-10 cm) were considered to have "high pain score LBPP" (hps-LBPP). RESULTS: The response rate was 83% (n = 891). A higher number of years of regular leisure physical activity (RLPA) decreased the risk of LBPP during pregnancy. The risk of hps-LBPP was increased for women who characterized their occupation as "mainly active" (OR = 2.0, 95% CI: 1.1-3.5) and "physically demanding" (OR = 1.9, 95% CI: 1.1-3.2). Visiting a physician as a result of LBPP was reported by 46.2%, and the mean number of visits was 2.0. One-third of women with LBPP had received treatment, as had half of women with hps-LBPP. CONCLUSIONS: A higher number of years of previous RLPA decreases the risk of LBPP during pregnancy. Occupations described as "mainly active" and "physically demanding" are associated with increased risk of hps-LBPP during pregnancy.