The aim of this study was to measure the incidence of high blood pressure (HBP) in a medium-size tannery in Botucatu, São Paulo State, southeast Brazil. A previous study at this tannery showed a high prevalence of arterial hypertension. A positive correlation was found between cumulated work time and arterial pressure. We followed a cohort of workers for seven years. At the end of this period, HBP incidence rate was calculated as 0.0964.year-1. This was considered high compared to other occupational groups.