The role of occupational environment in the occurrence of low-back pain was analyzed for 1719 commercial travelers (1376 men and 343 women). At the beginning of the study (T0) the group was interviewed to determine current lifestyle and occupational factors associated with low-back pain during the previous 12 months. Twelve months later (at T1), a subsample of 1118 persons (893 men, 225 women) was reinterviewed to study the association between the incidence of low-back pain during the year of follow-up and the risk factors at T0. At T0 low-back pain was significantly related with time spent driving a car at work, comfort of the car seat, carrying loads during work, standing for long periods at work, smoking, and psychosomatic factors. At T1 driving 10 h/week or more, seat comfort, and psychosomatic factors were associated with first occurrence of low-back pain.