Thirty young workers (aged 14 to 19 years) employed as groundskeepers and custodians were randomly assigned to two groups; one group received body mechanics instruction and the other did not. The instruction focused on proper spinal alignment in the work environment. Instruction on low back pain began with one classroom session before the subjects’ first day of work and continued during employment with two on-site sessions. The effect of instruction was evaluated through the observation of body mechanics during actual work performance. The results of the study indicate that the group that received instruction performed significantly better than the control group. This paper also discusses the occupational therapist’s role in providing job-specific body mechanics instruction in the work environment as a primary method of preventing low back pain.