A case-control studyof a heavily asbestos-exposed group was performed to determine if obstructive airway disorder is an independent risk factor for developing asbestos-associated malignacies. From a group of 1,500 asbestos workers who had previously undergone careful evaluation, 18 case employees were identified. Each case employee ws matched by smoking status, pack-years, age, and years of asbestos exposure to a single referent, a member of the same exposed population known to be free of malignancy. The spirometry results, obtained pior to the clinical manifestation of the cancer, were compared. The FEV1/FVC raio and the FEV1/ height3ratio were lower (P < .05 P < .10 respectively) in the case employees. These results suggest that obstructive airway disease maybe an independent risk factor for cancer.