Asthma is an important worldwide health problem. This study aimed to investigate the effect of soft tissue manipulation versus traditional physiotherapy program on a diaphragmatic excursion in asthmatic patients. Forty subjects ranged from 20 to 40 years were randomly assigned into two groups, Group I (n=20) received soft tissue manipulation of the upper cervical region (C0-1), upper dorsal region (T3-4), and thoracolumbar junction followed by muscle energy once weekly for 3 weeks and Group II (n=20) received traditional physiotherapy program (pursed-lip breathing exercise, diaphragmatic breathing exercise) ten repetitions each exercise per session three times a week for 3 weeks. The mean values of FEV1, maximum inspiratory pressure PEF, and diaphragmatic excursion (RT,LT) were significantly (p<0.001) increased from 2.80±0.16, 117.6±10.27, and 199.8±20.92, (RT 3.48±0.43, LT3.78±0.28) to 2.92±0.08, 134.75±5.81, and 259±61.6 (RT 4.33±0.27, LT 4.41±0.27), respectively in Group I, and from 2.66 ±0.12, 112.8±9.61, and 198.2±19.53 (RT3.36±0.41, LT 3.58±0.37) to2.75±0.13, 119.7±8.31, and 204.8±20.97 (RT3.52±0.44, LT 3.92±0.58), respectively in Group II, with an advantage in Group I. These findings suggested that soft tissue manipulation is more effective than traditional physiotherapy program on the diaphragmatic excursion and lung function in mild asthmatic patients.