Child sleep and adjustment research with community samples is on the rise with a recognized need of explicating this association. We examined reciprocal relations between children's sleep and their internalizing and externalizing symptoms using 3 waves of data spanning 5 years. Participants included 176 children at Time 1 (M = 8.68 years; 69% European American, 31% African American), 141 children at Time 2 (M = 10.70 years), and 113 children at Time 3 (M = 13.60 years). Children were from a wide range of socioeconomic backgrounds. Sleep was measured subjectively via self-reports and objectively via actigraphy and adjustment was assessed with parent and child reports. Cross-lagged panel models indicated that reduced sleep duration and worse sleep quality predicted greater depression, anxiety, and externalizing symptoms over time. To a lesser extent but supportive of reciprocal relations, adjustment predicted changes in sleep. Findings illustrate the reciprocal nature of relations between sleep and adjustment difficulties in otherwise typically developing youth.