A systematic review was conducted of school-based prevention and early intervention programs for anxiety. The aim of the review was to identify and describe the programs available, and to evaluate their effectiveness in reducing symptoms of anxiety. Twenty-seven outcome trials, describing 20 individual programs, were identified through the Cochrane Library, PsycInfo and PubMed databases. Results of the review indicated that most universal, selective and indicated prevention programs are effective in reducing symptoms of anxiety in children and adolescents, with effect sizes ranging from 0.11 to 1.37. Most programs targeted adolescents (59%), were aimed at reducing the symptoms of nonspecific anxiety (67%), and delivered cognitive behavioural therapy (CBT; 78%). Further quality school-based research is required that involves longer-term follow-up, the use of attention control conditions and evaluates teacher delivery.