This preliminary study evaluated the reliability and validity of the Japanese version of the Anxiety Sensitivity Index (ASI). Its test-retest reliability and internal consistency were found acceptable. Factor analysis of the ASI yielded 4 anxiety-related factors: factor I is heart/lung failure concern; factor II, psychological concern; factor III, physical concern; and factor IV, social concern. In addition, multiple regression analysis showed that the ASI score significantly correlated only with the neuroticism-related category of the NEO-Personality Inventory Revised. The ASI mean scores of those with 5 or more according to the General Health Questionnaire (unhealthy) and those with 16 or more according to the Center for Epidemiological Studies Depressive Scale (depression) were significantly higher than in the healthy and nondepressive groups. Although further research is necessary to confirm the construct validity by factor analysis of the ASI, the Japanese version of the ASI is applicable for use in the Japanese population.