A clinicopathological study of 21 patients who died as a result of chronic airways obstruction was carried out. Thirteen patients had been in right ventricular failure for at least one year before death and the other eight patients did not have right ventricular failure. The patients with long-standing right ventricular failure died at a younger age, on average, than those without failure. There were no significant quantitative differences between the two groups in the length of history of chest disease, blood gas estimations, respiratory function tests or degree of polycythaemia. The group with right ventricular failure had significantly larger mean right and left ventricular weights than the group without failure, but there were no significant differences in amounts of emphysema, size of bronchial mucous glands, proportion of small airways lumen in the lung or number of thick-walled peripheral lung vessels between the two groups. The findings did not support the division of this series of patients, with fatal chronic airways obstruction, into two distinct groups broadly defined as 'emphysematous' and 'bronchitic', either clinically or pathologically. A history of right ventricular failure correlated well with the finding of right ventricular hypertrophy at necropsy. Electrocardiographic evidence of right ventricular hypertrophy was found to correspond with the size of the right ventricle at necropsy in 66% of cases. The radiographic diagnosis of emphysema proved an accurate assessment when compared to the necropsy findings, and radiographic estimations of right ventricular enlargement were accurate in 65% of cases. Histological evidence of acute bronchitis was present in 20 of the 21 patients (95%), and five patients showed histological evidence of minor pulmonary thromboembolism. Ten patients in the series showed an increase in the weight of the left ventricular as well as the right ventricle.