Objective: To assess differences through grade 8 in diet, physical activity, and related health indicators of students who participated in the Child and Adolescent Trial for Cardiovascular Health (CATCH) school and family intervention from grades 3 through 5. Design: Follow-up of the 4- center, randomized, controlled field trial with 56 intervention and 40 control elementary schools. Participants: We studied 3714 (73%) of the initial CATCH cohort of 5106 students from ethnically diverse backgrounds in California, Louisiana, Minnesota, and Texas at grades 6, 7, and 8. Results: Self-reported daily energy intake from fat at baseline was virtually identical in the control (32.7%) and intervention (32.6%) groups. At grade 5, the intake for controls remained at 32.2%, while the intake for the intervention group declined to 30.3% (P<.001). At grade 8, the between-group differential was maintained (31.6% vs 30.6%, P = .01). Intervention students maintained significantly higher self-reported daily vigorous activity than control students (P = .001), although the difference declined from 13.6 minutes in grade 5 to 11.2, 10.8, and 8.8 minutes in grades 6, 7, and 8, respectively. Significant differences in favor of the intervention students also persisted at grade 8 for dietary knowledge and dietary intentions, but not for social support for physical activity. No impact on smoking behavior or stages of contemplating smoking was detected at grade 8. No significant differences were noted among physiologic indicators of body mass index, blood pressure, or serum lipid and cholesterol levels. Conclusion: The original CATCH results demonstrated that school-level interventions could modify school lunch and school physical education programs as well as influence student behaviors. This 3-year follow-up without further intervention suggests that the behavioral changes initiated during the elementary school years persisted to early adolescence for self-reported dietary and physical activity behaviors.