This study examined the relationship among children's sociometric status, qualities of mother-child interaction, and children's adjustment in first grade. Eighty-one 6-year-old children and their mothers participated in laboratory play interactions the summer before the children entered first grade. The interactions were coded later for warmth and control on the part of both mother and child. During the fall, the first graders were given individual sociometric interviews, and children were classified as popular, average, neglected, and rejected. During the spring, teacher ratings of child behavior problems and child competence were collected. Results showed that although maternal warmth and children's sociometric status were unrelated, both were significantly related to behavior problems and competencies in school. Children who were rejected by their peers and whose interactions with their mothers were low in warmth were rated by teachers as having more behavior problems and as less competent in certain respects than other rejected children; the children characterized by peer rejection and low maternal warmth also gave self-reports of their own social acceptance and cognitive competence that were more discrepant from objective information than did other rejected children. These effects either did not occur or were less pronounced within the group of children who were not rejected by their peers. Results were thus consistent with the idea that high maternal warmth served as a protective factor against adjustment difficulties associated with peer rejection.