Background: To date, there is scant knowledge and inconsistent results about physical activity, exercise and job strain in relation to pelvic girdle pain (PGP). Hence, the aims of the present study were: 1) determine prevalence of PGP and severe PGP during pregnancy and 2) compare background and lifestyle factors in addition to total physical activity level (at work, commuting, housework and recreational exercise) in those who experienced PGP and those who did not in pregnancy. Methods: Healthy pregnant women (n = 467) were allocated to the study from Oslo University Hospital, Norway. The participants filled in a validated self-administered questionnaire, Physical-Activity-Pregnancy-Questionnaire (PAPQ) in gestation-week 32 - 36. The questionnaire contained 53 questions with nine specific questions addressing PGP. The key question on PGP was asked cross-sectionally and also posed retrospectively for pre-pregnancy, 1^st and 2^nd trimester (During this pregnancy, did you experience any PGP?) (“Yes versus No”). Results: More than half of the women (57.5%) reported to suffer from PGP, with 18.4% reporting severe PGP. Compared the no-PGP group, women with PGP were significantly more likely to be sick-listed, multiparous, they perceived their job to be physically demanding, as well as had physically demanding household chores, including childcare. In addition, they were more prone to have experienced PGP in previous pregnancies and suffered from urinary incontinence (UI) in the current pregnancy. Most women with severe PGP reported to be sedentary in the 3^rd trimester; however they performed more strengthening exercises at home than the women without PGP. Severe PGP also showed an association with standing/walking ≥50% at work. Conclusion: Women who exercised regularly in the 3^rd trimester were less likely to report PGP, while job strain was associated with higher prevalence of PGP. There is a need for a prospective study with larger sample size to further evaluate if exercise has any causal association with PGP.