Mobile Decision Support for Advanced Practice Nurses (MODS-APN) is a PDA-based decision support tool designed to assist APNs in the diagnosis and management of smoking cessation, obesity, and depression. It is currently being tested in a randomized, controlled trial (RCT) in a sample of APN students to determine the effect on adherence to clinical practice guideline (CPG) recommendations. Tools such as MODS-APN have the potential to increase CPG adherence, enhance evidence-based practice, promote patient safety, and in the long term improve patient outcomes.