The results of the administration of the California Achievement Tests (CAT) to students in the Montgomery County Public Schools, Maryland (MCPS) are presented. The battery is administered in the fall of each school year to students in grades three, five, and eight under a state mandate. The CAT is administered to students in Grade 11 under a local requirement. Countywide results are presented with a historical perspective, and interpreted by racial/ethnic and sex classifications. MCPS students' performance on the CAT improved in the 1983 administration. Scores are superior to the performance of the national norm group. Trend data by school and racial/ethnic group for students tested in MCPS more than once are presented, as well as graphic presentations of county and school results. Scores were slightly higher for females than males on the total test across grade levels. School results are presented in four forms: (1) average subject and total test scores for four years; (2) average subtest scores for 1983; (3) total test interquartile range; and (4) longitudinal and nonlongitudinal trends. The two appendices contain detailed summary data and a glossary of technical testing terms. (DWH)