To assess the factor validity and reliability for the Japanese version of the Aberrant Behavior Checklist-Community (ABC-Community), 322 subjects with moderate to profound mental retardation (188 males and 134 females, mean age 29.79 +/- 12.45) were rated by the staff at the residential facilities in Wakayama Prefecture, Japan. Rating data were analyzed by factor analysis using the principal factoring method with iteration, followed by oblique rotation. The internal consistency was estimated by Cronbach's alpha. Of these subjects, 43 were rated twice with an interval of 4 weeks to confirm the test-retest reliability and 33 were rated by pairs of raters for interrater reliability. Forty-eight of 58 items loaded most heavily on the same factors as in the original factor solution. Coefficient alpha raged from .85 to .95 across five subscales. The test-retest reliability was high with Spearman's rank correlation coefficient ranging from .84 to .90. Although the correlation coefficients for interrater reliability tests were somewhat lower (.58 to .78), they were all statistically significant (p < .001). The Japanese version of ABC Community was comparative to the original and was useful for assessing behavior problems in Japanese persons with mental retardation.