Exposure to metalworking fluid has been shown to cause health problems among workers. The aim of this study was to compare health outcomes and levels of exposure among workers exposed to metalworking fluid before and after the implementation of preventive measures. The frequencies of self-reported symptoms, as well as the concentrations of measured substances were lower after the implementation of preventive measures. Logistic regression showed statistically significant differences in the report of irritations, a stuffy or runny nose, eye irritation, a hoarse or dry throat and a cough with odds ratios of 0.31 (95% CI 0.21–0.47), 0.12 (95% CI 0.05–0.29), 0.13 (95% CI 0.06–0.28) and 0.24 (95% CI 0.12–0.46), respectively. This confirms the efficiency of the performed intervention and highlights the importance of eliminating the recirculation of contaminated air.