To evaluate the efficacy of an 8-week worksite nutrition education intervention for university staff using the Health Belief Model (HBM) to promote healthful dietary behaviors that reduce risks for cardiovascular disease and cancer. 2 3 2 repeated measures baseline/posttest ex post facto research design. Staff employees were randomly assigned to treatment (n = 28) and control groups (n = 25). The intervention focused on specific health beliefs, nutrition knowledge, and dietary practices to demonstrate treatment effect. Dependent variables were specific health beliefs, nutrition knowledge, and dietary behaviors. Independent variables were demographic characteristics and group assignment. Tests of parametric assumptions, power analyses, analysis of variance, and Kuder-Richardson and Pearson product-moment coefficients were computed and specificity of treatment effects was assessed. Perceived benefits of healthy nutrition practices and nutrition knowledge related to cardiovascular disease and cancer significantly improved among the treatment participants, P <.001. Treatment group participants also significantly reduced total calories, fat, saturated fat, and cholesterol intake (each P <.001). The intervention appears to be related to treatment effects and significantly increased nutrition knowledge and decreased energy, fat, saturated fat, and cholesterol intake to levels consistent with national recommendations.