The relationships of lung function to physical characteristics in young adults have not been adequately described for different gender-race groups in the United States. As part of a study of the effects of ozone exposure upon Black and White men and women, the authors measured lung volumes, expiratory flow rates, and airway resistance on a sample of 314 healthy 18-35 yr old nonsmokers. Regression analysis indicated that lung function was adequately described as a linear function of either height or sitting height in each of the four groups, and that while not always significant, gender and race differences in the height and sitting height coefficients were consistently present with those of males and Whites larger than those of females and Blacks, respectively. Lung volumes were frequently observed to be associated with body mass index as measured by Quetelet Index. The best fitting gender-race specific multiple regression models including these terms and occasional age terms are presented.