We report the case of a severe bronchial asthma attack 15 minutes after the ingestion of food containing small amounts of alcohol. Although an ethanol inhalation test was negative, an acetaldehyde inhalation test was positive. Furthermore, it was discovered that the patient was homozygous for a mutation of the aldehyde dehydrogenase-2 (ALDH-2) gene. We subsequently diagnosed his attack as acute severe alcohol-induced asthma. Since bronchial asthma patients who are homozygous for mutant ALDH-2 genes are susceptible to acute severe alcohol-induced asthma attacks, strict clinical attention is thought a necessity.