The relationship of low-back pain (LBP) to work history and work environment factors was studied in a randomized sample of 940 men from 40 to 47 years of age. The life-time incidence of LBP was 61%, the prevalence 31%. In a univariate analysis ten of the variables studied were found to be correlated to the occurrence of LBP: less overtime work, diminished work satisfaction, decreased potential to influence the work situation, lesser demand on concentration, monotonous work, physically heavy work, a high degree of lifting, to a lesser degree sitting, and to a greater standing and walking work posture. When a covariance analysis was applied to these variables, only three had a direct association to LBP. They were less overtime work, monotonous work, and a high degree of lifting.