The inverse relationship between peripheral leukocyte count and forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC), previously reported in employed men, was investigated in women and men in a representative national sample. Leukocyte count was negatively correlated with FEV1 and FVC in most age, sex, and smoking subgroups in whites. In linear regression analyses controlling for age, height, and smoking variables, leukocyte count was significantly associated with FEV1 and FVC in white men (P < .05) and white women (P < .002). In "never smokers," significant independent associations were seen for leukocyte count and FVC in white men (P = .01) and FEV1 in white women (P = .02). These findings confirm an independent association of leukocyte count with pulmonary function in white men and extend the findings to white women.