The contexts of family and peer group play critical roles in shaping children's lives over their development. Biological theory suggests that these two contexts are interlinked to impact children's daily lives and should be examined in integrated models. The present study examined relationship quality with peers as a potential mediator that links maternal parenting style to children's school adjustment. Two dimensions of parenting style--maternal responsiveness and behavioral control, and three aspects of school adjustment--academic grades, problem behaviors in the school setting, and school related experiences of stress, were investigated. The mediation models were tested concurrently and longitudinally in a sample of 347 children during their 4th to 5th grades. Biological theory also suggests personal characteristics as one of the defining factors that influence developmental outcomes. Thus, child gender and child ethnicity were included as moderators in the proposed models. Using multiple regressions, results of the study indicated both dimensions of maternal parenting style and peer relationship quality were linked to children's well-being at school concurrently. Surprisingly, peer relationship quality was unassociated with behavioral problems. Short-term longitudinal associations were found between behavioral control and GPA and between responsiveness and school related stress. In terms of mediation, only maternal responsiveness had indirect effects on one of children's outcome variables via its influence on peer relationships concurrently. Also, moderation effects were not found in the proposed mediation models