Background. The aim of this study was to determine the prevalence of self-reported pelvic girdle pain in pregnancy and study the impact on function, the use of crutches, and waking up at night, according to location of pain. Methods. A population-based questionnaire study was performed among all women 18–40 years in two communities in Norway in 1998–99. A total of 1,817 women with a prior delivery constituted the study sample. Pelvic girdle pain was grouped into five categories: pain in anterior pelvis, in posterior pelvis, in anterior and unilateral posterior pelvis, in anterior and bilateral posterior pelvis (a complete pelvic girdle syndrome), and pelvic pain with no information on location. Results. A total of 46% (843/1,817) reported pelvic girdle pain in pregnancy at one location or more. Nineteen percent reported pain in anterior pelvis only, 14% in posterior pelvis only, 4% in anterior and unilateral posterior pelvis, and 5% reported a complete pelvic girdle syndrome. A total of 7% of all pregnant women used crutches during pregnancy and 15% reported waking up at night frequently due to pelvic girdle pain. A complete pelvic girdle syndrome, as compared to pain in the anterior pelvis only, was strongly associated with the use of crutches (adjusted odds ratio (OR) 4.3; 95% confidence interval (CI) 2.5–7.4) and with waking up at night due to pain (OR 4.6; 95% CI 2.7–7.2). Conclusion. Pain related to the pelvic joints is common among pregnant women in Norway and may cause serious functional problems.