This study explores the impact of one-to-one computing on student achievement in Ohio high schools as measured by performance on the Ohio Graduation Test (OGT). The sample included 24 treatment schools that were individually paired with a similar control school. An interrupted time series methodology was deployed to examine OGT data over a period of 5 to 8 years. Overall student performance and content-specific achievement in math, reading, science, social studies, and writing were not significantly affected by the introduction of 1:1 computing. Treatment schools using a netbook device produced the greatest overall change in scores.