Compared 6 self-rating measures of loneliness and associated phenomena, designed for use with elementary-school children. Three samples of children in Grades 5 and 6 (total N = 758) completed various combinations of these instruments. In terms of internal consistency, the Children's Loneliness Scale (CLS) and the peer-related loneliness subscale of the Loneliness and Aloneness Scale for Children and Adolescents (LACA) were most reliable. Substantial support was obtained for the convergent validity of the measures. Confirmatory factor analysis (CFA) on 2 samples and exploratory factor analysis on a third sample indicated that the 13 scales and derivative subscales of the 6 measures tapped 4 different but interrelated latent constructs: peer-related loneliness, family-related loneliness (in some cases restricted to parent-related loneliness), negative attitude toward being alone, and positive attitude toward being alone. Recommendations are offered for conditions under which each scale may be useful. Limitations of this study are discussed and suggestions for future research are offered.