Background. Faculty members developed diabetic ketoacidosis (DKA) guidelines based on the current American Diabetes Association guidelines. Objectives. To evaluate the impact of a multidisciplinary approach to implementing DKA guidelines on residents' knowledge, guideline compliance, and patient outcomes. Design. Longitudinal case-control study with 2 arms. Setting. University-affiliated teaching hospital in Fresno, California. Methods. A Web-based testing software (TestWare) was used for educational/ assessment testing before and after DKA guidelines implementation. Patients' charts were reviewed to determine the degree of guideline compliance, patient care charges, and length of stay before and after DKA guidelines introduction. Results. Testing scores improved from 48% to 54% correct answers after implementation of the guidelines (P = .06). Overall, guidelines compliance improved from 67% to 88% (P < .05). Conclusion. A multidisciplinary intervention including knowledge assessment, individualized education, and formal didactic teaching was effective at improving knowledge and guideline compliance in DKA for internal medicine residents.