The Dimensional Assessment of Personality Pathology, Basic Questionnaire (DAPP-BQ) was developed to assess 18 personality traits that provide a systematic representation of personality disorder. This study investigates the reliability and validity of the Japanese version of the DAPP-BQ and the relationship between the DAPP-BQ and Revised NEO Personality Inventory (NEO-PI-R) in a heterogeneous general population sample (n = 1485). Internal consistency (coefficient alpha) and test-retest reliability over a 3-week period was satisfactory for all scales. Factor analysis yielded 4 factors labeled "emotional dysregulation," "dissocial behavior," "inhibition," and "compulsivity" that accounted for 76.0% of the total variance. Subsequently, we investigated the relationships between the 18 dimensions and the 5 dimensions of the NEO-PI-R in a second heterogeneous general population sample (n = 717). Combined factor analysis of the 2 scales again yielded 4 factors accounting for 70.4% of the total variance. Finally, we used multiple regression analyses to examine the extent to which the 5 NEO-PI-R scales could be used to predict individual DAPP-BQ scales. These indicated that the NEO-PI-R does not have content that covers some DAPP-BQ dimensions, especially conduct problems, narcissism, and stimulus seeking.