Pulmonary function was assessed by spirometry in 3,076 elderly Japanese-American men of the Honolulu Heart Program (HHP) cohort. The assessment was done with a stringent quality assurance program that adhered to American Thoracic Society (ATS) recommendations for spirometry. Less than 6% of the participants were unable to perform three acceptable spirometry maneuvers. A "healthy" subgroup of 528 men between the ages of 71 and 90 yr was identified by excluding almost all smokers and subjects with lung disease and other factors negatively influencing FEV1. Reference equations and normal ranges for FEV1, FVC, and the FEV1/FVC ratio were derived from the healthy group. Use of prediction equations from the Cardiovascular Health Study (CHS) of elderly European-American men consistently overpredicted FVC by 0.3 to 0.4 L and FEV1 by 0.15 L. Men in the HHP were on average 11 cm shorter than those in the CHS. Use of a prediction equation derived from the HHP cohort when the men in the cohort were on average 22.6 yr younger consistently overpredicted FEV1 by 0.2 to 0.3 L. These results underscore the importance of using prediction equations appropriate to the ethnicity, age, and height characteristics of the subjects being studied.