Prescription Learning is a multimedia diagnostic prescriptive program providing individualized instruction coordinated by Prescription Learning Corporation. One high school, nine elementary schools, and four middle schools provided this supplemental reading and mathematics instruction to students covered by the provisions of Chapter 1 of the Education Consolidation and Improvement Act. Prescriptions based on placement test results included objectives and strategies for a total of 1,333 students in kindergarten through grade 8 in the Portland (Oregon) School District. Prescription Learning students made an equivalent rate of growth in project and preproject years in most areas. In 1984-85 the growth rate of project students was greater and statistically significant for reading, and positive, but not significant, in mathematics. It is recommended that Prescription Learning be an option along with other District programs for Chapter 1 and other educationally disadvantaged students. Seven data tables are provided, and Appendix A contains 10 tables of growth rate figures. (SLD)