 Objectives of this double blind randomized controlled trial are to study the effect of oral administration of morphine SR on health-related quality of life, respiratory adverse effects, and functional capacity; to explore whether description and severity of breathlessness are related with a clinically relevant response to morphine and to analyse the cost-effectiveness of morphine SR. The study population will consist of 124 clinically stable outpatients with COPD and severe dyspnea despite optimal pharmacological and non-pharmacological treatment. 