Two studies describe the development of a comprehensive, vignette-based measure of social information processing (SIP) particularly relevant for children with internalizing problems. Study 1 (N = 219 3rd-6th graders) describes the creation of the Children's Evaluation of Everyday Social Encounters Questionnaire (ChEESE-Q) and evidence for its reliability and validity, including internal structure and relation of SIP variables to depressive and anxious symptoms. Study 2 (N = 127 5th-6th graders) replicated the factor structure and validity evidence found in Study 1 and provided support for the reliability of alternate forms of the ChEESE-Q. Overall, results supported ChEESE-Q scores' moderate temporal stability and internal consistency in assessing SIP. Results also supported the presence of positive- and negative-valenced SIP patterns. Child internalizing symptoms were strongly related to a negative SIP style across both depression and anxiety, whereas only depressive symptoms were negatively associated with positive aspects of SIP. (Contains 3 tables, 1 figure and 1 footnote.)