Students in grades 3 to 8, who participated in the Follow Through program in Portland, Oregon, were tested for their reading and mathematics achievement during Fall 1979, Spring and Fall 1980, and Spring 1981. The measuring instrument used was the Portland Basic Skills Achievement Levels Testing Program. Test results were reported as RIT (Rasch achievement unit) scores. The data for Follow Through students were compared with achievement data for control groups, achievement data for all students in the Portland School District, and national norms. This report presents the results of the comparison in the form of graphs and tables. It is concluded that the Portland Follow Through program has consistently raised and sustained basic skills achievement scores significantly above the control group and even above national norms, and that the effects have been more pronounced in reading than in mathematics. (MJL)