Internet-based health interventions (IHIs) provide a way to treat people via the Internet. The spectrum is wide, comprising interventions for mental disorders and somatic diseases as well as health and risk behavior change interventions. Numerous international studies have demonstrated the efficacy of IHIs for the aforementioned areas. Through the resource-saving applications IHIs are cost-efficient, not least suggesting their usefulness for medical rehabilitation. The present overview starts with a description of IHIs with a differentiation of technical-formal and thematic aspects. In doing so, the focus lies primarily on cognitive-behavioral treatment approaches, as the best scientifically investigated IHIs to date. An overview of the empirical evidence of IHIs is given, followed by a discussion of the implementation possibilities in medical rehabilitation.