The purpose of this study was to obtain information about the knowledge and attitudes of Italian oncology nurses concerning cancer pain management and to determine the predictors of nurses' pain management knowledge. The study was a nationwide descriptive survey and included 287 nurses in Italy from 21 oncology wards in the north, center and south of Italy. The Nurses' Knowledge and Attitudes Survey (Italian version) and a background information form were used to collect the data. Knowledge and attitudes regarding cancer pain were the main research variables. Among the 39 pain knowledge questions assessed, the mean number of correctly answered question was 21.4 (SD=5.5), with a range of 6-35. The correct answer rate for the entire scale, on average, was 55% (SD=25.9). Further analysis of items showed that more than 50% of oncology nurses underestimated the patients' pain and they did not treat it in the correct way; they also had an incorrect self-evaluation about their pain management knowledge. Results from stepwise regression showed that nurses with higher mean correct answer scores had attended more courses about pain education. There are still significant knowledge deficits and erroneous beliefs that may hamper treatment of oncology patients in pain. The results of this study could be useful to institutions involved in patient care and teaching of pain management.