This study tests the ability of classroom emotional climate to moderate anxious solitary children's risk for peer exclusion over a 3-year period from 3rd through 5th grade. Six hundred eighty-eight children completed peer nominations for anxious solitude and peer exclusion in the fall and spring semesters of each grade, and observations of classroom emotional climate were conducted at the same time points. Results revealed a positive relation between anxious solitude and peer exclusion in the fall semester of each grade. However, in classrooms with supportive versus unsupportive emotional climates, this relation demonstrated a different pattern of change from fall to spring semesters. In classrooms with supportive emotional climates, children with high versus low levels of anxious solitude experienced relative elevation in fall peer exclusion, but this disappeared by the spring, such that spring peer exclusion levels were equalized among children who differed in anxious solitude. This result is consistent with hypotheses guided by the Child x Environment model. However, in classrooms with unsupportive emotional climates, results did not conform to expectations that children with high anxious solitude would experience stable or increased peer exclusion over time. (Contains 5 tables and 6 figures.)