Anxiety disorders are prevalent mental disorders that are a significant burden on the community. There are effective treatments available, but many people do not seek treatment and there is a lack of professionals available to provide evidence-based treatment to all those with anxiety disorders. Recently, there has been increased attention on ways to cost effectively meet the demand for treatment with minimal cost to health services. Self-help efforts have been proposed to play a role, either as an initial minimal treatment in stepped-care models of treatment, or as strategies undertaken by an individual to prevent a full disorder developing. This review examines what is known from randomized controlled trials about the efficacy of self-help interventions for anxiety disorders.