Background: Studies reporting inadequate nursing care for patients indicate that nurses are negatively affected in such situations, and research is needed to study nursing care in postoperative situations. Objective: To describe situations of postoperative pain management in a surgical ward in Thailand. Methods: A qualitative approach using the Critical Incident Technique was chosen to investigate situations of postoperative pain management from the perspective of surgical nurses in Thailand. Data were collected through multiple semi-structured interviews with nine nurses over a five-week period. Results: The situations of surgical nurses described three elements that heavily influenced the quality of postoperative pain management: engagement in a trustful nurse-patient relationship, availability of pain medication and nursing care when needed, and imbalance between meeting the patient’s needs and completing routine nursing duties. Conclusion: The results help to expand our understanding of how Thai nurses manage pain in postoperative situations and indicate areas that could be improved in terms of how nurses respond to patients’ pain. Nurses challenge existing guidelines and facilitate development of new nursing guidelines and/or policies in pain management.