Numerous studies have demonstrated the association between procrastination and poor physical and mental health outcomes. In addition, it is clear that procrastination on wellness behaviors such as exercise as well as treatment delay plays an important role in this association. Despite the clear relation of procrastination and negative health outcomes, there is no validated self-report measure of health-related procrastination. This chapter presents the measurement development and psychometric properties of a new measure, the Health-Related Procrastination Measure (HPM). The HPM is a context-specific self-report measure that can be adapted to quantify procrastinating behavior on specific health behaviors (e.g., exercise, scheduling medical appointments, diet), so it can be used as a set of stand-alone scales for specific health behaviors. As an example of this approach, we present the psychometric properties of two specific scales based on the HPM model that measure physical activity (i.e., Exercise Procrastination Scale) and healthy diet (i.e., Healthy Diet Procrastination Scale). After item creation, content validity analysis, and refinement, the instruments were administered to a community sample of 111 adults as well as a sample of 277 undergraduate students. Both classical-test theory and item-response theory were used to refine and evaluate the measure simultaneously. Our preliminary findings related to the factor structure, convergent, divergent, and criterion validity of the Exercise Procrastination Scale (EPS) and Healthy Diet Procrastination Scale (HDPS) supported the construct validity of the scales. Our analysis also suggested that the scales are reliable measures with relatively good discriminatory power.