This study is the first prospective study correlating smoking and drinking among Japanese adolescents. The aim of the study is to determine if adolescent smoking experience predicts future adult alcohol abuse. We conducted a longitudinal prospective study on adolescent drinking from 1997 to 2007. The study subjects were about 800 male and female junior high school students. Their mean age was 13.5 years old at the starting point. We conducted surveys by post on the subjects concerning drinking status, alcohol-related problems and smoking experience once a year for 10 years. This study attempted to determine if smoking experiences in 1999 (mean age, 15.8 years old) correlated with alcohol abuse in 2005 (mean age, 22 years old) among the subjects of the prospective study. The result showed that male students who had had smoking experiences in 1999 were more likely to become alcohol abusers in 2005 than those without smoking experiences according to the AUDIT. On the other hand, females with smoking experiences as teenagers showed no correlation with alcohol abuse as young adults. Adolescent tobacco use could be called a gateway drug to adult alcohol abuse among Japanese males, but not among females.