A survey of hospital staff nurses of a large tertiary care hospital was performed to investigate occupational low-back pain. Attack rates of 41% (37% "occupational") and 52% (occupational) were found using recall periods of two weeks and six months, respectively. Comparison with a control group suggests the validity of the work-relatedness of low-back pain in nurses. Factors associated with the disorder were also investigated, with results showing no differences due to nursing division assignment but significant association with specific tasks.