Purpose: This study was to investigate the factors influencing problem behaviors among adolescents. Method: The subjects for this study were 596 students in middle school in Seoul. The data was collected during the period from May to November; 2001 by use of questionnaires. The instruments used were the Child Problem Behavior list by Hong (1986), the Body Cathexis Scale by Secord and Jourard(l953), and the Beck Depression Inventory by Beck(l978). The data was analyzed by using the SPSS- Win program. Result: Problem behaviors showed a significant negative correlation, with body image (r=-.310. p=.000) and positive correlation with depression (r=.674, p=.000). There were significant differences in the problem behavior scores of subjects according to sex, family status, economic status, and school scores. Female students were found to have a high degree of internalized problem behaviors. In addition, depression, body image, and sex were significant predictors to explain problem behaviors(47.3%). Depression, sex, grade, and school scores were significant predictors to explain externalized problem behaviors(21.9%) and depression and body image, internalized problem behaviors(51.4%). Conclusion: Since predicting factors of problem behaviors among middle school students by problem behavior type and sex were different, then practitioners should consider these differences when developing programs for them.