A mathematics and science program for gifted and talented junior high students in Brooklyn, New York was designed to provide accelerated and enriched instruction in mathematics and enriched instruction in science and computer science. This program was evaluated to determine the congitive and affective changes that would indicate student growth and positive effects of the program and to determine what aspects of the program could be improved. Results show: (1) increases in overall mathematics performance, but no gains in achievement related to geometry or real numbers; (2) increases in overall science and biology achievement, but no gains in chemistry achievement; (3) positive student attitudes (toward school) at the beginning of the school year, but no increase during the year; (4) large gains in all areas of the computer science test; and (5) positive parent ratings of student performance in 14 school-related behaviors. In addition, subjects who belonged to a school computer club outperformed students who did not belong to the club. Recommendations are offered based on these and other findings. Two suggestions offered are to devote more class time to teaching chemistry and to revise the program's admission policy. (JN)