Background: Exercise therapy is a core component of pulmonary rehabilitation for `patients with interstitial lung disease to enhance cardiorespiratory fitness and physical capacity. The study aimed to evaluate the effect of a rehabilitation exercise protocol on physical capacity of elderly patients with exacerbated interstitial lung disease. Research design: A quasi-experimental research design (study/control) was utilized. Setting: The study was conducted in the chest intensive care unit, the chest department, and the chest outpatient clinic at Minia University Hospital-Egypt. Sample: A purposive sample of 86 elderly patients with exacerbated interstitial lung disease distributed equally into study and control group. Tools: Tool I: Patient health assessment included socio-demographic and medical data. Tool II: Functional Capacity Assessment involved (Six Minute Walk Distance Test, Modified Medical Research Council Dyspnea Scale, Katz Index of Independence in Activities of Daily Living and Oxford Scale for evaluating Muscle Strength). Results: The study group showed a significant increase in the mean score of distance walked after 8 weeks of rehabilitation protocol. In addition, it was observed that 0 % and 23.3 % of the study and control group had dyspnea after 8 weeks of implementing the rehabilitation protocol. As for, katz index scale, a statistical significance difference between the two groups was observed after 8 weeks of implementing the exercise rehabilitation. Conclusion: Application of rehabilitation exercise protocol documented a significant increase in physical capacity of elderly patients with exacerbated interstitial lung disease. Recommendation: Establishing exercise training programs for patients with exacerbated interstitial lung disease that contain multi-component interventions.