The aim of this study was to analyze the current practices on acute pain management of patients under opioid maintenance treatment (OMT), that is, buprenorphine or methadone. A total of 706 physicians were solicited through a national network to answer a survey about pain perception and analgesic strategies. Among the prescribers, 323 (46%) answered the survey: 131 (40%) physicians estimated that patients under OMT when exposed to an acute painful event feel more pain than other patients and 170 (53%) estimated that the patients felt the same amount of pain. Use of WHO step 1 analgesics was reported by 283 (88%) prescribers [264 (82%) prescribers reported use of paracetamol and 178 (55%) reported use of NSAIDs]. Among the second-line analgesic drugs, the WHO step 3 analgesics (mainly morphine) were the most commonly reported [221 physicians (68%)]. Overall, the results demonstrate the misconceptions of physicians on the pain tolerance of patients under OMT. Clinical studies and evidence-based guidelines are necessary to improve the therapeutic strategies for such patients in an emergency setting.