This document presents a study on school effectiveness as a function of organizational structure, culture, and programs in private elementary schools. The study aimed to determine the profiles of principals, assess the level of effectiveness of organizational structure, culture and programs, identify differences in perceptions between principals and teachers, examine trends in achievement test results, and propose monitoring guidelines. Key findings include that principals and teachers rated organizational structure, culture and programs as "very satisfactory". Principals and teachers differed in their perceptions of organizational structure and culture but not programs. Most schools showed improving achievement test results. Monitoring guidelines were proposed to help schools sustain quality.