PURPOSE: The purpose of this study was to describe and to analyze real conversation about polite behavior of nurses in cancer units. METHODS: This study was conducted using a Brown & Levinson(1987) theory to analyze the polite behavior of nurses in cancer units. Five nurses who participated in this research gave permission to be videotaped. The data was collected from January to February, 2006. RESULTS: Polite behavior of nurses in cancer units consisted of greetings, emotional support, open questions and indirect direction. And impolite behavior of nurses in cancer units was using the medical terminology, repetition of direct speech acts and task-oriented conversation. CONCLUSION: This study suggests polite behavior strategies for effective nursing conversation with cancer patients. Therefore, the findings may provide basic raw materials for educational programmes and intervention studies.