We conducted a randomized controlled trial involving Japanese junior college students aimed at investigating the effects of a single session of alcohol health education concerning the effects of alcohol, alcohol-related health problems, and drinking behavior. Students were randomly assigned to an intervention (n = 38) or a control group (n = 33). The intervention group attended a 90-minute alcohol health education session that included demonstration of an ethanol patch test, watching videos, and a lecture by an ex-alcoholic. The control group received health education regarding smoking. The students' knowledge regarding alcohol, their drinking behavior, and problem drinking (CAGE) were measured by a self-administered questionnaire at the baseline and at a two-month follow-up. A repeated measures of analysis of variance (ANOVA) of those who completed the follow-up indicated the education sessions' significant intervention (group x time) effect on the scores related to knowledge of alcohol-related health problems (p = 0.035), with a greater increase in the scores of the intervention group at the follow-up. No significant intervention effect was observed regarding drinking behavior or problem drinking as measured by CAGE (p > 0.05). Alcohol-related education can be considered an effective way to increase awareness of alcohol-related health problems, but less effective for changing drinking the behavior of Japanese junior college students. Copyright© 2007 by Okayama University Medical School.