OBJECTIVES: Dyspnea is a major issue for patients suffering from respiratory diseases. The MDP questionnaire was developed as a tool to evaluate both the sensory and emotional dimensions of dyspnea. The MDP still needed to be validated in a clinical setting context. The aim of this study was to validate the psychometric properties of the MDP. METHODS: A prospective, multicenter and observational study was conducted in patients with chronic obstructive pulmonary disease (COPD) at three times of assessment (inclusion visit, 3 and 3.5 months after) in France. The MDP includes 11 items (1: unpleasantness; 5: sensory dimension and 5: emotional dimension) to compute the immediate perception score (sensory and unpleasantness items) and the emotional score (emotional items). The construct validity (using multi-trait), the concurrent and clinical validity (tested by comparison with MMRC, CAT, SF-12, DIRECT, K6, MCS, HADS and clinical parameters), internal consistency reliability and test-retest reliability allowed assessing the psychometric properties of the MDP. RESULTS: The main population included 276 patients (mean age=58, 78.4% male) with COPD at different severity stages. All sensory and emotional items met both convergent and discriminant validity criteria, confirming the structure of the questionnaire. Psychometric scores matched standards for clinical validity (the worse the health status of the patient, the worse the scores; more impacted from GOLD stage II to IV and from MMRC grade 3 to 4), concurrent validity (majority of correlations between 0.40 and 0.70), internal consistency reliability (Cronbach’s alpha=0.89 and 0.82 for sensory and emotional dimensions, respectively) and test-retest reliability (intraclass correlations=0.84 and 0.86 for immediate perception and emotional scores, respectively). CONCLUSIONS: The MDP questionnaire is a valid and reliable instrument to measure both sensory and emotional dimensions of dyspnea perceived by COPD patients in a clinical setting context. Further studies will be necessary to evaluate the responsiveness of the questionnaire.