Three measures of self-concept or self-esteem and one measure of social competency development, designed for young children, are assessed. The instruments assessed include: (1) the Martinek-Zaichkowski Self-Control Scale for Children (MZSCSC); (2) the Behavioral Academic Self-Esteem Scale (BASE); (3) the Piers-Harris Children's Self-Concept Scale (PHCSC); and (4) the Kindergarten Inventory of Developing Social Competency (KIDSc). Salient aspects of the 25-item MZSCSC, which was normed for children in grades 1 through 8, include adaptability to children without verbal skills, minimal discrimination among children with adequate self-concepts, assessment of effects of teaching styles, and minimal testing of psychometric properties. Salient aspects of the BASE, which was normed for children in kindergarten through grade 8 and for 4-year-old preschoolers, include a strong factor structure, a range of applications, and substantial data on psychometric properties. Salient aspects of the PHCSCS, which is a self-report measure for children and adolescents, include: a strong factor structure; substantial data on psychometric properties; applicability to screening, clinical, and educational purposes for individuals; and program and intervention evaluation. The KIDSc may provide a measure of self-concept accepting assumptions similar to the PHCSCS, but it is limited to events related to kindergarten. The primary value of the KIDSc as an indicator of self-concept would be for a narrow age range and in a narrow focus (academic/school related rather than global). A 36-item list of references and a 15-item bibliography of other self-concept measures are included. (TJH)