This study examined the relationship between the Big Five personality and two dimensions of attachment, namely, anxiety and avoidance, in Japanese young adults. Junior college and vocational school students, 242 in all, participated in the study. Multiple regression analyses showed that Neuroticism and Agreeableness were predictors for anxiety, and Extraversion and Openness were predictors for avoidance. In addition, the coefficients of determination were relatively small. These results were almost the same as previous overseas studies. This suggested that although attachment dimensions had correlations with the Big Five personality to some extent, they measured different characteristics.