The purpose of this study was to explore emergency department (ED) physicians' perspectives of guidelines for effective communication. More specifically, the ways in which physicians manage the tensions among effective communication dimensions framed by relational dialectics theory are examined. This study used in-depth interviews with 17 ED physicians and 70 hours of observations to identify five dimensions of effective communication: efficiency, clarity/accuracy, relevance, comprehension, and rapport. Two communication tensions resulted from these dimensions: efficiency versus rapport and efficiency versus comprehension. In almost all instances, physicians chose efficient communication at the expense of comprehension or rapport. In addition, there was a tension between patient and physician perspectives of clarity and relevance that physicians tended to resolve by emphasizing what was relevant and clear from their own perspective. Implications for managing tensions in terms of efficiency and a physician-centered approach are discussed.