Background and objective: The Medical Research Council dyspnoea score (MRCDS) is a simple, objective scale to assess dyspnoea, the main complaint in patients with chronic interstitial lung disease (ILD). We sought to investigate whether MRCDS is a predictor of outcome in patients with chronic ILD. Methods: One hundred and fifteen patients (50 idiopathic pulmonary fibrosis (IPF) and 65 non-IPF ILD) were retrospectively studied. Baseline (time of diagnosis) MRCDS and 3-6-month changes were considered. Endpoints were (i) 18-month clinical progression, defined as either: >= 10% absolute reduction in forced vital capacity (FVC) percent predicted; >= 50-m decline in 6-min walk distance; hospitalization for respiratory causes; lung transplantation (LTx) assessment or death and (ii) 18-month survival. Results: At the end of the observation period, 54 subjects (47%) experienced clinical progression (including 22 deaths and 3 LTx). In patients with IPF, a longitudinal increase in MRCDS predicted clinical progression significantly (area under the curve (AUC) = 0.76, sensitivity = 62%, specificity = 91%); baseline MRCDS was a strong predictor of mortality (AUC = 0.80, sensitivity = 87%, specificity = 57%). In patients with non-IPF ILD, longitudinal increases in MRCDS, but not baseline values, were predictive of both clinical progression (AUC = 0.81, sensitivity = 85%, specificity = 77%) and mortality (AUC = 0.76, sensitivity = 91%, specificity = 61%). Considering the whole population, MRCDS increase and FVC decline were independent predictors of mortality. Conclusion: Longitudinal increases of MRCDS predict poor outcome in chronic ILD, with good accuracy. Baseline MRCDS remains a strong predictor of mortality in IPF. MRCDS should be included in the global assessment of the clinical course of chronic ILD.