Sleep duration and media use (i.e., computer use and television viewing) have important implications for the health and well-being of children. Population data suggest that shorter sleep duration and excessive screen time are growing problems among children and could be interacting issues. This study examined whether bidirectional relationships exist between sleep duration and media use among children, and whether these associations are moderated by child- and household-related factors. The results supported the hypotheses that bidirectional relationships exist between sleep duration and media use among children. These findings are important given recent population trends for increased media use and shorter sleep durations among children.