Nursing Care Plans (NCP) and Nursing Clinical Practice Guidelines (NCPG) promote evidence-based patient care, but in their paper form they are difficult to be applied at the point-of-care. We present our approach to generate patient-specific nursing care plans by modeling and computerizing these nursing knowledge resources. We present a Nursing CarePlan Ontology (NCO) that models the NCP and NCPG to realize an integrated knowledge base for designing and executing patient-specific nursing CarePlans. We adapted METHONTOLOGY methodology for ontology engineering to develop our OWL-based NCO, and instantiated a set of NCP and NCPG. We have developed an execution engine that provides recommendations to nurses based on the patient's data. NCO was successfully evaluated for representational accuracy and completeness using a set of test NCP and NCPG.