This research evaluated effects of a multi-media computer-based instruction (CBI) program designed to teach grocery store purchasing skills to three high-school students with intellectual disabilities. A multiple baseline design across participants used measures of computer performance mastery and grocery store probes to evaluate the CBI. All participants initially performed at low percentages of correct responses in purchasing items at grocery store checkout stands. Following introduction of CBI, all participants increased correct purchasing skills. Additionally, all participants performed at high levels in generalization probes at three different grocery stores and in a 30-day follow-up probe. Participants and parents rated purchasing skills higher following treatment. Results are discussed in terms of increased purchasing skills using CBI, generalization, maintenance, and implications for practice. (Contains 1 figure and 1 table.)