The purpose of this review was to summarize current knowledge concerning the role of psychological workplace variables in back pain. To this end the literature on psychological factors and back pain was systematically searched and analyzed. Psychological and medical databases and cross-referencing were used to locate 975 studies. To be included in this review, studies had to have a prospective design, include a psychological predictor variable, report on back pain, and be published in English. Twenty-one studies fulfilled the criteria for psychological workplace factors. The results showed a clear association between psychological variables and future back pain. There was strong evidence that job satisfaction, monotonous tasks, work relations, demands, stress, and perceived ability to work were related to future back pain problems. Further, moderate evidence was established for work pace, control, emotional effort at work, and the belief that work is dangerous. There was inconclusive evidence about work content. The attributable fraction indicated that substantial reductions in the number of cases of back pain could be achieved if the exposure to the psychological risk factor was eliminated. Although the methodological quality of the studies varied, they were deemed to provide "best evidence," and the consistency of the findings suggests that they are relatively robust. It is concluded that psychological work factors play a significant role in future back pain problems. However, there is still a lack of knowledge concerning the mechanisms by which these operate. These results suggest that a change in the way we view and deal with back pain is needed. Applying knowledge about psychological factors at work might enhance prevention as well as rehabilitation.