The Fairfax County, Virginia, Schools' Primary Mathematics Program (PMP) was re-evaluated to provide additional data on program effectiveness and to provide suggestions on future program development, implementation, and improvement. Seventy-one teachers in 14 schools implemented the pilot program. Evaluative data included interviews with 14 principals, teacher surveys, observations of student and teacher behavior, and California Achievement Tests scores of second grade PMP students versus those in 61 classrooms in 14 comparison schools. Results indicated that teacher and principal attitudes toward PMP were positive. Expected behaviors were confirmed as far as teaching strategies, use of instructional and manipulative materials, and student behavior. Although teachers and principals felt that PMP children had greater understanding of mathematics concepts than comparison groups, the PMP students' achievement levels on the California Achievement Tests were the same as their counterparts in the comparison classrooms. Factors which were found to impede program implementation were student evaluation procedures, PMP ability to meet the needs of advanced students, and teacher time required for lesson planning and management of materials. Facilitative factors included program developers' assistance, teacher training, integration of textbooks and manipulative materials, and colleagues' support. Most principals favored the expansion of PMP to include grade 3. Various evaluation instruments and results are appended. (GDC)