Objectives To estimate the prevalence of leucopenia among industrial workers 2000–2009.

Methods The study population comprises workers from manufacturing industries of the Bahia State, Brazil, who had annual compulsory medical checkups in a national not-for-profit occupational safety and health care system during the study period. We retrieved computerised medical records, clinical and laboratory exams, and also workplace risk assessment, occupational and socio-demographic data. Leucopenia was defined as having leucocytes counting less than 4000.

Results From a total of 64 454 workers with valid blood counting data, 12 303 (19.09%) had leucopenia over the study time. Prevalence of leucopenia was 21.87% in 2005, 20.73% in 2006 showing a declining trend until 2009 when reached 15.89% (p < 0.001). Leucopenia was higher among male workers than women (p < 0.001) and in the rubber and plastic industry.

Conclusions Blood cell counting is compusory monitored in industry, by data are rarely analysed and results made public. Preliminary results of our analysis show that there is a declining trend of leucopenia prevalence suggesting a possible positive impact of the Benzene National Agreement on workers’ health in the rubber and plastic industry in Bahia.