BACKGROUND: According to previous studies, it was suggested that coffee consumption may protect liver toxicity caused by alcohol drinking. Our study is design to analyze association between coffee consumption and serum gamma glutamyltransferase(GGT) in alcohol drinking male adults. METHODS: From 1996 May to 1995 July, data were collected from alcohol drinking male adults who visited a university hospitals for health check up. Among them, subjects who had disease could affect liver function test were excluded. Sociodemographic data, alcohol drinking amount, smoking status, coffee drinking amount data were collected by questionnaire and subject's weight and height were measured. RESULTS: We excluded 12 male adults because they had a disease which may cause liver dysfunction. In analysis of variance, coffee consumption and BMI were significantly associated with serum GGT(p=0.023). Alcohol drinking and cigarettes smoking were not significantly associated with GGT. In multiple regression analysis, coffee consumption was inversely related to serum GGT levels independently(p=0.002). Cigarettes smoking was also independently and positively associated with serum GGT levels(p=0.040). CONCLUSION: Coffee consumption may lower serum GGT levels in alcohol drinking male. It may suggest that coffee consumption protect liver toxicity caused by alcohol drinking and It must be validated in large sized prospective study involving non alcohol drinker.