The relation of chronic air-flow limitation and respiratory mucus hypersecretion to all causes of mortality was studied in a population of 1,061 men working in the Paris area, surveyed initially in 1960/1961, and followed for 22 yr. During this period, 369 deaths occurred; VC, FEV1, FEV1/H3, and FEV1/VC were significantly associated with mortality, even when age, smoking, occupational dust exposure, and chronic phlegm were taken into account. Besides the obstructive disorder, the hypersecretory disorder (chronic phlegm) was significantly associated with mortality. Controlling, using Cox's model, for age, FEV1/H3, smoking habits, and dust exposure, all factors associated with chronic mucus hypersecretion and mortality, showed that phlegm production remained significantly related to death (relative risk, = 1.35; p less than 0.01). Although relatively weak, this relationship is not negligible in terms of public health because of the high prevalence of chronic phlegm.