Pediatric hospitalists frequently interact with clinical decision support (CDS) tools in patient care and use these tools for quality improvement or research. In this method/ology paper, we provide an introduction and practical approach to developing and evaluating CDS tools within the electronic health record. First, we define CDS and describe the types of CDS interventions that exist. We then outline a stepwise approach to CDS development, which begins with defining the problem and understanding the system. We present a framework for metric development and then describe tools that can be used for CDS design (eg, 5 Rights of CDS, “10 commandments,” usability heuristics, human-centered design) and testing (eg, validation, simulation, usability testing). We review approaches to evaluating CDS tools, which range from randomized studies to traditional quality improvement methods. Lastly, we discuss practical considerations for implementing CDS, including the assessment of a project team’s skills and an organization’s information technology resources.