Previous studies have implicated CYP1A1 and GSTM1 polymorphisms as risk factors for various cancers. A number of studies have been devoted to the association of CYP1A1 or GSTM1 polymorphism with susceptibility to oral carcinoma and have yielded conflicting results. The aim of the present study was to assess the possible associations of oral cancer risk with CYP1A1 genetic variation and GSTM1 null genotype respectively via systematic meta-analyses. The data suggest that variant genotypes of CYP1A1 might not be risk factors for oral cancer, whereas GSTM1 null genotype significantly increases susceptibility to oral cancer in Asians but not Caucasians.