To investigate knowledge levels and attitudes regarding pain management among nurses working in medical units in Hong Kong and factors that might influence their knowledge and attitudes. Pain, a common symptom for patients in medical units, can be relieved by effective pain management. Nurses have a vital role in implementing pain management effectively and must, therefore, have a solid foundation of knowledge and a positive attitude towards pain management. Cross-sectional study. A self-administered survey including demographics and the nurses' knowledge and attitudes survey regarding pain-Chinese version (NKASRP-C) was completed by 143 nurses working at medical units in a public hospital. Descriptive statistics and stepwise regression were used in the data analysis. A deficit in knowledge and attitudes related to pain management was prominent (percentage of total score = 47.72, range = 20-76%). Although nurses had developed appropriate attitudes towards pain management, discrepancies between practice and attitudes existed. Those with a higher percentage of correct scores in NKASRP-C had longer clinical working experience and applied knowledge of pain to their daily work. The findings of this study, identifying problems of inadequate knowledge and inappropriate attitudes regarding pain management, are of concern. A better understanding of the factors that affect such knowledge and attitudes and of the discrepancy between attitudes and practice, can provide useful information to be included in education programmes for nurses and to inform policy on the provision of pain management.