Background: Health behaviors in childhood and adolescence are implicated in health behaviors and chronic disease risk in adulthood for the majority of the US population. However, little is known about these relationships in Hawaiian youth. This study investigated the extent to which childhood physical activity (PA) and fruit and vegetable consumption behaviors predicted later behaviors across a 10-year period in Hawaiian youth. Methods: Three cohorts of fourth- to sixth-grade students who participated in an elementary after-school program (Fun 5) provided baseline data (Y1—data collected between 2003 and 2007), 5-year (Y5—data collected between 2008 and 2012), and 10-year (Y10—data collected between 2013 and 2017) follow-up surveys. Demographic, PA, and fruit and vegetable consumption measures were completed at all 3 time points. Bivariate and multiple regressions were computed in 2018. Results: Y1 and Y5 behavior predicted PA in young adulthood. For fruit and vegetable consumption, Y1 behavior predicted Y5 behavior but not Y10 behavior, and Y5 behavior predicted Y10 behaviors. Conclusions: Similar to mainland US youth, it is important to address PA and nutrition early in the life span for Hawaiian youth to increase long-term preventive health behaviors and reduce long-term chronic disease risk.