The purpose of this study was to compare the academic achievement of 543 urban 4th- (n=291) and 8th- (n=252) grade students who attended Montessori or traditional education programs. The majority of the sample consisted of minority students (approximately 53 percent), and was considered low income (approximately 67 percent). Students who attended a public Montessori school were compared with students who attended structured magnet, open magnet, and traditional non-magnet public schools on standardized measures of math and language arts. Results of the study failed to support the hypothesis that enrollment in a Montessori school was associated with higher academic achievement.