Dyspnoea is cardinal symptom in chronic obstructive lung disease and common in palliative phases of cancer and other chronic medical diseases. Low-dose opioids is frequently used off-label. This review examines the evidence and safety as well as administration forms and pharmacokinetics using low dose opioids for dyspnoea. Conclusively, there seems to be clinical efficacy although further studies are needed. Furthermore, the authors recommend Danish Medical Agency to legislate low-dose morphine to palliative patients with refractory dyspnoea.