The authors present a rationale for developing core competencies for training and organizational development in extension. Core competencies are defined as "the basic knowledge, attitudes, skills, and observable behaviors that lead to excellence in the workplace." Competency-based models can be used to create an infrastructure that promotes innovation and continuous learning in every dimension of an extension organization. Competency models are designed around the skills individuals and groups need to be effective now and in the future. Competencies must be tied directly to the mission and strategic issues of the organization. A ten-step model is offered for identifying, validating and developing core competencies for an extension training and organizational development system. The seven core competencies developed by North Carolina Cooperative Extension using this process are defined. These competencies are being used or adapted by several states in the Southern Extension Region of the United States, and extension organizations throughout the United States are beginning to develop competency-based models for training and development. Illustrations of the application of the core competencies in North Carolina are provided along with preliminary qualitative evidence of the impact of this approach.