The authors developed the Interpersonal Behavior Questionnaire for Children with the aim of assessing the constructs of the interpersonal circumplex model, that is, Dominance and Love and their possible combinations, via third- to fifth-grade children's self- and peer reports. In the three studies presented herein, the authors examined several psychometric properties of the questionnaire. Results demonstrated that children's ratings along the questionnaire yielded the hypothesized circumplex structure of the interpersonal variables; that they reached significant association levels with external criteria; and that they were reliable. Specifically, interrater correlations were shown to reach substantive levels when inspected in older children, when scores were aggregated over raters, and when dominant behaviors were evaluated. Overall, the findings demonstrated the tenability of the circumplex model in young ages via children's ratings. The authors suggest that both personality assessment and personality development research may take advantage from using children's evaluations, in addition to adults' ratings of their children's personality. (Contains 3 notes, 10 tables and 3 figures.)