Behavior ratings and self-report measures of child and adolescent psychopathology are often used to explore the types and extent of psychological disorders in youth. Yet a review of the literature suggests that parent, teacher, and self-report of psychopathology are not generally highly correlated. Moreover, even among the same type of rater (e.g., parents), there is often very little concordance in ratings. Although there is a substantial literature related to the circumstances under which different informants can be expected to correlate, there is little to guide psychologists in clinical decision making. The present article briefly reviews issues related to both rater and child characteristics that affect the quality and utility of their ratings. The child characteristics of age, setting, and type of problem and the relationship of these to rating quality are highlighted. Last, suggestions are made about which rater should be given the most weight and when. (Contains 1 figure, 1 table and 1 note.)