Lung volumes (FVC1, FEV1.0 and peak flow) were measured in 403 men and 561 women volunteers for fitness testing, using the SRL automated spirometer system. Average scores for this population were 5–10% higher than predicted from age, height and sex using either the formulae inherent in the SRL computer or standards proposed by Anderson et al. [1968] for the Toronto population; existing standards may thus underestimate respiratory potential. Lung function data showed a dose-dependent decrease within the category of cigarette smokers, but there was no significant difference between average results for smokers and non-smokers. Multivariate analysis showed significant contributions of lean mass and obesity to the overall description of lung volumes; however, effects were not large enough to justify incorporation of such variables into routine prediction equations. Positive responses to the respiratory section of the Cornell Medical Index were in several instances associated with below expected lung volumes. The most consistent response was to the question ‘do you suffer from asthma?’ Although the average effect was significant, the magnitude of response (10–20%) would have been overlooked in individual testing; this suggests that there may be more scope for pulmonary screening through the improvement of questionnaires than through the purchase of expensive electronic spirometers