This study examines convergent and divergent validity for middle childhood anxious solitude, unsociability, and peer exclusion as assessed by five informants (peers, teachers, observers, the self, and parents). Participants were 163 (67 male, 96 female) third grade children (M age = 8.70 years). Parent reports were available for a subset of the sample (N = 95). Validity was analyzed via multitrait-multimethod correlation matrices and structural equation models. Results indicate that anxious solitude and peer exclusion have better convergent and divergent validity than unsociability, although there is evidence of shared method variance for all constructs. Peers have the best combination of convergent and divergent validity, and parents, the worst; teachers, observers, and the self demonstrated mid-level validity.