The effects of self efficacy and tool design on the relationships between age and performance, absenteeism, and job satisfaction were examined in 311 employees of a meat packing facility. Employee information was obtained from questionnaires and interviews. Control variables included job tenure, physical job demands, and gender. Tool design and self efficacy were significantly correlated. While age was positively associated with job satisfaction, relationships between age and absenteeism or performance were not established. In addition, age was not related to self efficacy, tool design, physical job demands, or job category. Men tended to be employed in more physically demanding jobs than women. Employees who rated their tools as poor also tended to rate their jobs as physically demanding. Job satisfaction was higher among employees with high self efficacy and a positive perception of tool design. Hierarchical regression analysis was used to assess the effects of self efficacy and tool design on work outcomes. Although self efficacy exerted a significant effect on the relationship between age and absenteeism, it did not affect the associations between age and performance or job satisfaction. Increased self efficacy was related to decreased absenteeism among older workers, but not among younger workers. Although tool design significantly affected the relationship between age and performance, it did not influence the associations between age and absenteeism or satisfaction. The youngest and oldest workers tended to perform more poorly than workers of intermediate age. Tool design had a greater impact on the performance of older workers than on that of younger workers.