Objectives: Alcohol intake has been reported to be a risk factor of laryngeal cancer. Since the aldehyde dehydrogenase 2 (ALDH2) genotype is a major determinant of personal alcohol drinking habit, there is a possibility that ALDH2 genotype would be a risk factor for laryngeal cancer. N-Acetyltransferase 2 (NAT2) is a detoxifying enzyme and its polymorphism has been reported to be related to the risk of many environmental cancers. However, studies on the associations between these two genotypes and laryngeal cancer risk are scarce. We have assessed the effects of alcohol intake and the genotype of ALDH2 and NAT2 on the risk of laryngeal cancer in Koreans. Materials and Methods: Eighty-four pathologically proven laryngeal cancer patients and 168 age matched controls were included as the study subjects. Information about alcohol intake and smoking habit was collected using a self administered questionnaire. ALDH2 and NAT2 genotypes were analyzed using PCR-RFLP methods. Results: Alcohol intake was significant as a risk factor for laryngeal cancer (OR : 2.58, 95% CI : 1.24, 5.36), especially for supraglottic laryngeal cancer (OR : 3.24, 95% CI : 1.02, 10.31). Personal drinking habit was closely related with personal smoking habit, which was a potent risk factor of laryngeal cancer. In a stratified analysis according to the level of cumulative smoking amount, drinking was significant neither in light smokers (equal or less than 30 pack-years) nor in heavy smoker (over 30 pack-years). The ALDH2 genotype was significantly associated with the risk of laryngeal cancer in a univariate analysis. The statistical significance, however, disappeared after adjusting alcohol intake using a multiple conditional logistic model. The NAT2 genotype was not significant as a risk factor for laryngeal cancer. Conclusion: Alcohol drinking and ALDH2 genotype would have indirect effects on laryngeal cancer by their correlations with cigarette smoking or with alcohol drinking. It is less likely that the NAT2 genotype would be a potent risk factor of laryngeal cancer.