While research has shown that sleep problems and substance use are reciprocally associated in adults, much less is known about this association in early adolescence. The main aim of the current longitudinal study was to explore bidirectional relationships between sleep problems, substance use, internalizing and externalizing problems in young adolescents. A prospective design was used incorporating two waves (approximately 1 year interval). A total of 555 young adolescents (290 females, M age = 13.96) participated in this study. All participants completed self-report measures in classrooms during regular school hours (questionnaires about sleep quality and sleep hygiene were used to measure sleep problems). The results indicated that sleep problems predicted changes in substance use, internalizing and externalizing problems over time, but problem behaviours did not predict changes in sleep problems, adjusted for gender, age and puberty. One exception was that alcohol use negatively predicted changes in sleep problems. This study suggests that sleep problems are important precursors of substance use, internalizing and externalizing problems in adolescence.