The objective of the present study was to evaluate the genotoxicity of a combination exposure to lead and smoking in workers from the printing industry and also to examine the possible interaction between the two agents. Individuals were classified into 4 different groups: control group, lead-exposed group, smokers and the double-exposure group. Chromosomal analysis was carried out according to conventional methods. Our preliminary study shows that lead-exposed individuals had a significantly increased frequency of sister chromatid exchanges. Further, double exposure to smoking and lead inhibits mitosis.