This study examined the factor structure of the Strengths and Difficulties Questionnaire (SDQ) in urban inner-city and suburban general population samples of American youth. The SDQ was administered to 4,661 predominantly minority urban youth (mean age = 13.0 years, SD = 2.02) and 937 predominantly Caucasian suburban youth (mean age = 14.0 years, SD = 1.56). The authors examined SDQ factor structure using structural equation modeling techniques. The fit for the 5-factor models in both samples was very good (comparative fit index = .96-.97). However, the factor loadings and, correspondingly, the scale reliabilities for most of the SDQ scales (except for Emotional Problems) were low, which suggests poor specificity of the items. Subsequent exploratory and confirmatory factor analyses suggested that a 3-factor structure had a comparable model fit and better internal consistency of the scales. The study concluded that, although the SDQ scales do conform reasonably well to a 5-factor model, the scales are unsatisfactory in other respects and that, in its present form, the instrument has inadequate psychometric characteristics. Future research is needed for further scale development. (Contains 4 tables and 2 figures.)