Although low back pain (LBP), a major problem for nurses, is presumed to be caused by the physical demands of work, little scientific information supports this view. In this study, registered nurses were surveyed regarding LBP, demographics, medical history, exercise, and work variables. Univariate and multivariate analyses indicated previous LBP or back pain in another location of the spine were strongly associated with LBP during the study year. Aerobic dance exercise was less strongly associated. In contrast, lifting patients was only weakly associated, and other occupational variables not at all. Although results must be interpreted cautiously in light of study limitations, the findings suggest that factors unrelated to work may be more important to LBP than previously thought.