This evaluation of the i-SAFE Internet safety curriculum is one of the first research efforts to examine the effectiveness of Internet safety education on the knowledge and behavior of school-aged children. The outcome evaluation found that the curriculum was effective in increasing children’s knowledge about Internet safety. There were positive and significant changes in knowledge between the treatment and comparison groups, both on average and over time. For the most part, there were no significant changes in behavior between the treatment and comparison groups. However, given the low levels of risky behavior documented at baseline, it would be difficult to detect behavioral change in this context. I-SAFE America is a non-profit foundation helping children understand issues surrounding Internet safety. Founded in 1988, i-SAFE consists of three components: education, outreach, and the Youth Empowerment Campaign. In 2001, the U.S. Department of Justice, National Institute of Justice (NIJ) awarded Caliber Associates a grant to conduct a quasi-experimental study of the effectiveness of the i-SAFE curriculum. NIJ was specifically interested in obtaining answers to the following questions: (1) do students retain knowledge received during i-SAFE lessons, (2) do students use the knowledge, and (3) at what reduced levels or intensities of implementation are program benefits no longer measurable? This study is an important step towards developing a knowledge base about what works in Internet safety education. The study was implemented in 18 schools (12 treatment and 6 comparison schools) in 6 sites with more than 2,000 children. The evaluation had 2 key components: a process evaluation, focusing on implementation characteristics, and an outcome evaluation.