The objective of this study was to assess the effect of a passive trunk exoskeleton on functional performance and metabolic costs in healthy individuals. Functional performance of 12 work-related tasks was assessed based on objective outcome measures and perceived task difficulty. In addition, we measured energy expenditure during 5 min of repetitive lifting and walking, with and without exoskeleton. Wearing the exoskeleton tended to increase objective performance in static forward bending. Performance in tasks that involved hip flexion decreased and these were perceived as more difficult with the exoskeleton. Wearing the exoskeleton during lifting decreased metabolic costs by as much as 17%, and may reduce the development of fatigue and LBP risk. During walking, metabolic costs increased by 17%. These results indicate the potential efficacy of the exoskeleton to support trunk bending tasks, but also stress the need to allow disengagement of support depending on activities performed.