Individual susceptibility to chemically induced cancer may be partly explained by genetic differences in the activation and detoxification of procarcinogens. Numerous polymorphisms of metabolism genes have been identified and their role in individual susceptibility to cancer has been observed. Many studies have shown that variant CYP1A1 alleles combined with GSTM1 and GSTT1 nulls genotype are associated with an increased risk of lung cancer. In this study, we evaluated genetic polymorphisms in CYP1A1 (*2B and *4), GSTM1 and GSTT1 and risk of lung cancer in Rebouças tunnel workers (Rio de Janeiro, Brazil). Deletions of GSTM1 and GSTT1 genes were detected in samples from control group. In an exposure group, single deletions of GSTM1 or GSTT1 genes were also detected. In our study, the same individual showed CYP1A1*2B polymorphism and deletions of GSTM1 and GSTT1 gens. These results demonstrate that this individual exposed to occupational pollution at Rebouças tunnel, may have intensified metabolizing pollutants such as PAH, and have difficulties in detoxification of metabolites of these pollutants, increasing the risk of lung cancer development.