Questionnaires were sent to qualified nurses (QN) and nursing aides (NA) to study the prevalence of low-back pain (LBP) and sciatica in relation to age, work-load, free time activities, menstruation, pregnancies and number of children. LBP and sciatica severe enough to make them unfit for daily tasks were significantly more common in NA. Back injury and disability pension due to sciatic symptoms were also more common in NA. Occupationally, NA had twice the amount of lifting, bending and rotation, while QN reported more sitting and standing at work. Under the age of 30, the heaviness of the work was related to LBP in both NA and QN. Prevention should be directed to improvements in the occupational work load, particularly for younger nurses.