The hypothesis of this study was that noise exposure level and job complexity interact to affect changes in blood pressure (BP) levels and job satisfaction over 2-4 years of follow-up. Results showed that among workers exposed to high noise, those with complex jobs showed increases in BP that were more than double shown by those with simple jobs. Under low noise exposure, there was a small increase in BP for workers with complex jobs but about a 3-fold increase in workers with simple jobs. The prevalence of elevated BP showed a similar trend. Job satisfaction increased among workers with complex jobs but was much less in those exposed to high noise. It was concluded that exposure to occupational noise has a greater negative impact on changes in BP and job satisfaction over time among those performing complex jobs. In contrast, job complexity had a clear beneficial effect for workers exposed to low noise.