This chapter advances research on media literacy by reviewing studies that utilize media literacy in either short -term or long -term interventions. Media literacy interventions on a wide array of topics including violence, smoking, alcohol, and advertising are reviewed. Effectiveness of media literacy is discussed using various criteria: duration of intervention, intervention design, target group, intervention modality, causal process, and different strategies for media literacy interventions. Key questions addressed in this chapter ask how media literacy effi cacy is defi ned, and what issues surround media literacy effi cacy.