Clinical Pathways (CP) stipulate an evidence-based patient care workflow for a specific disease within a localized setting. We present an ontology-based approach for computerizing CP so that they can be executed at the point-of-care. We present our CP modeling approach that features the integration of multiple localized CP to realize a unified disease-specific CP. The execution of the ontological CP model is achieved by our property abstraction method that assigns functional behaviors to existing semantic properties to facilitate their execution. Using our methods we have developed a prostate cancer management system.