We performed spirometry on 177 male healthy children from Patiala, North India between 10 to 19 years age. The best fit regression equations for different functions were determined for each parameter. A linear relationship of lung function was observed with age, height, weight and BSA. Our results have been higher than the South Indian studies but closer to other North Indian studies. Similar comparison with western studies reveals that their subjects have higher lung function values than our subjects. It is clear that grossly erroneous conclusions may be reached unless prediction equations for lung function tests for a given ethnic group are derived from studies upon the same ethnic group.