Objective: Examine the short-term and long-term impact of speed of processing training on cognitive performance in older adults. Study Design: Randomly assigned, 2-group experimental design with assessment periods at baseline, immediately after training, and at 2 subsequent annual points. Setting: Laboratory. Participants: Older adults (N=159) with speed of processing impairments. Interventions: Speed of processing training group or a social contact Internet control group. Participants in both groups received approximately ten 1-hr training sessions. Main Outcome Measures: Cognitive measures. Results: Speed of processing training resulted in improved performance on two measures of information processing (Useful Field of View and the Starry Night tests). Conclusions: Speed of processing training produced significant processing speed improvement that was robust over a 2-year period. Copyright 2007 by the American Psychological Association.