PURPOSE: The purpose of this study was to determine the effect of nurses' pain experience on the inference of their patients' suffering. METHOD: Study subjects were sampled from 184 nurses who worked in general wards in one S university hospital located at Seoul. Nurses' pain experience consists of personal pain experience and professional pain experience. The Standard Measure of Inference of Suffering (Davitz and Davitz, 1981) was used for suffering inference measure, and patients' suffering which consists of physical pain and psychological distress. RESULT: Suffering inference scores of nurses without personal pain experience revealed a higher value than that of nurses with personal pain experience. But these differences were not statistically significant. The higher intense pain was experienced, the higher were suffering inference scores. This physical pain inference score was statistically significant(p=.044). Of the nurses who had personal pain experience, suffering inference scores of nurses with unrelieved pain experience revealed a higher value than that of nurses with relieved pain experience. Physical pain and psychological distress inference scores were statistically significant(p=.010, p=.006). Suffering inference scores of nurses without professional pain experience(internal medicine, general surgery, orthopedic surgery) revealed a higher value than that of nurses with professional pain experience. Professional pain experience of internal medical illness was statistically significant in psychological distress of internal medical illness (p=.044), and professional pain experience of orthopedic surgical illness was statistically significant in physical pain of orthopedic surgical illness(p=.027). CONCLUSION: Nurses who have experienced low pain intensity or good pain relief are inclined n to underestimate patient' pain. Although nurses who care for the same patient over a long time deal skillfully with that patient, nurses are inclined to underestimate that patients' pain. Nurses need to be aware of possible biases related to pain assessment as a result of pain experience.