This study assessed the impact on tenth grade students of attending high schools whose practices are consistent with the school-restructuring movement. Using data on a sample of 11,794 sophomores in 830 high schools from the first two waves of the National Educational Longitudinal Study of 1988 (NELS:88), the authors evaluated restructuring effects on students' gains in engagement and achievement in four subjects and the social distribution of those gains. High schools with several practices consistent with restructuring and those with none of the 30 practices that were considered were contrasted with schools that engaged in only traditional reforms. School size was evaluated as an independent structural feature. The results revealed that students' gains in achievement and engagement were significantly higher in schools with restructuring practices and lower in schools without reforms. Higher and more socially equitable engagement and achievement were consistently associated with smaller high schools.