Social cognitive theory (SC) provides a theoretical framework to evaluate improved quality-of-life (QOL) outcomes through interventions with cancer patients To assess whether inclusion of SCT components predicted better outcomes, focused comparisons were used to integrate results from 38 randomized studies. Interventions with more SCT components had significantly larger effect sizes than studies with fewer or no SCT components for the overall analysis (Z = 3.72, p < .01). Subanalyses of affective, social, objective physical outcome, and specific QOL measures revealed that SCT-based interventions had significantly higher effect sizes; inclusion of SCT components resulted in significantly lower effect sizes on subjective physical and functional outcomes. Results suggest that using SCT-based interventions maximizes improvement in overall QOL outcomes for adult cancer patients.