Background: Sleep complaints are highly prevalent in adolescents suffering from major depressive disorder (MDD). The aims of this study were to describe the longitudinal course of sleep complaints, and to assess the association between sleep complaints and clinical outcome in a sample of adolescents with MDD during naturalistic follow-up.Methods: A sample of adolescent outpatients (n = 166; age 13-19 years, 17.5% boys) diagnosed with MDD was followed-up during one year in naturalistic settings. Sleep symptoms and psychiatric symptoms were assessed with interviews and self-report questionnaires.Results: All sleep complaints were less frequent at one-year follow-up compared to baseline. Baseline sleep complaints did not adversely affect clinical outcome at one-year follow-up: severity of the sleep complaints at baseline was associated with a steeper improvement of depressive and anxiety symptoms, suicidality/self-harm symptoms, and overall psychosocial functioning over time.Conclusions: Our results suggest that sleep disturbances at baseline do not necessarily lead to poorer clinical outcome during follow-up. Larger longitudinal studies combining both subjective and objective measures of sleep in depressed adolescents are needed to clarify the link between sleep and depression further.