The purpose of the authors' research was to create a tool to evaluate science, technology, engineering, and mathematics (STEM) literacy in service-learning projects. The researchers posited that components of service-learning, which in this case included the deliverable and reflections, are examples of fundamental STEM literacy and thus can be assessed for STEM learning outcomes. The authors review the literature on service-learning and on STEM literacy. Combining components of literacy-based learning objectives and service-learning objectives with the revised Bloom's taxonomy in a taxonomy table, they created a general STEM literacy evaluation tool. They then applied the tool to a service-learning project as a case study. The results indicate that the tool effectively evaluated students' STEM literacy in a service-learning project and that it can be used to determine which literacy components, such as individual knowledge categories and learning objectives, were predictive of successful STEM literacy.