Exercise is the body’s most common physiologic stress, and it places major demands on the cardiopulmonary system. Spirometry is considered the most practical test of assessing the respiratory function.so the present study was carried out to know the effect of acute excercises on pulmonary function test. A total of 100 1st M.B.B.S. students (M=50, F=50,) were included in the study and the changes in PFTs before and after acute exercise of 6 minutes (queen’s step test) of those Students were recorded. Results were analyzed using paired and unpaired t-test. The study concluded that the spirometric variables increased after acute exercise and the values were higher in boys than in girls.