Patients who are taking atypical antipsychotic medications have a high incidence of metabolic complications, including increased weight, waist circumference, blood sugar, lipid levels, and blood pressure. In 2004, the American Diabetic Association and three other associations, including the American Psychiatric Association, developed guidelines to screen for metabolic syndrome, but in practice, adherence to the guidelines vary. This article describes a process to implement the guidelines in a suburban psychiatric day treatment hospital using Rogers' Diffusion of Innovations model. Measurement of waist circumference was identified as an opportunity to improve the current metabolic screening protocol. Post-intervention evaluation revealed increased adherence to the guidelines (0% pre versus 95% post). Adherence to the guidelines demonstrates the effect of the systematic application of Rogers' model on acceptance of practice change. Fully implementing the guidelines meets recommendations for the standard of practice and can improve the health and quality of life of patients prescribed atypical antipsychotic medications.