Background: Oncology nurses play a crucial role in cancer pain management and must be highly informed to ensure their effective practice in the cancer setting. The aim of this study was to determine the baseline level of knowledge and attitudes of oncology nurses regarding cancer pain management. Materials and Methods: A cross-sectional survey research design was employed. The sample comprised 58 cancer nurses working in Shahid Sadoughi hospital, Yazd, Iran. The ‘’Nurses Knowledge and Attitudes Survey Regarding Pain’’ (NKAS) tool and a demographic form were utilized to ascertain the knowledge and attitudes of oncology nurses working in oncology settings. Results: The average correct response rate for oncology nurses was 66.6%, ranging from 12.1% to 94.8%. The nurses mean score on the knowledge and attitudes survey regarding pain management was 28.5%. Results revealed that the mean percentage score overall was 65.7%. Only 8.6% of nurse participants obtained a passing score of 75% or greater. Widespread knowledge deficits and poor attitudes were noted in this study, particularly regard pharmacological management of pain. Conclusions: The present study provides important information about knowledge deficits in pain management among oncology nurses and limited training regarding pain management. Our results support the universal concern of inadequate knowledge and attitudes of nurses regarding cancer pain. It is suggested educational and quality improvement initiatives in pain management could enhance nurses knowledge in the area of pain and possibly improve practice.