Clinical guidelines systematically assist practitioners with providing appropriate health care for specific clinical circumstances. However, a significant number of guidelines are lacking in quality. In this paper, we use the UML modeling language to capture guidelines and model checking techniques for their verification. We have established a classification of possible properties to be verified in a guideline and we present an automated approach based on a translation from UML to PROMELA, the input language of the SPIN model checker. Our approach is illustrated with a guideline based on a guideline published by the National Guideline Clearing House (NGC).