The effects of variations in work load (indexed by paid work hours) on psychological well-being, cortisol, smoking, and alcohol consumption were examined in a sample of 71 workers (44 women, 27 men) in the retail industry. Measures were obtained on four occasions over a six-month period, and assessments were ranked individually according to hours of work over the past seven days. Job strain (demand/control) and job social support were evaluated as potential moderators of responses. Paid work hours ranged from a mean of 32.6 to 48.0 hours per week, and ratings of work-home conflict and perceived stress varied across assessments. Salivary cortisol was inversely associated with job strain and did not vary across sessions. Female but not male smokers consumed more cigarettes during periods of long work hours, and self-reported smoking and cotinine concentrations were greater among smokers with higher nicotine dependency scores. Men but not women with poor social supports consumed more alcohol as work hours lengthened. These data indicate that health behaviors are affected only to a limited extent by variations in work load. Results are discussed in the context of adaptation to work and the pathways linking stressful experience with health risk.