Introduction: According to WHO, a stroke refers to rapidly developing clinical signs of focal (or global) disturbance of cerebral functions, with symptoms lasting 24 hours or longer or leading to death. The damage caused by a stroke can interrupt your normal swallowing and food or fluid is entered into your airways and lungs. Dysphagia can damage the lungs, which can trigger a lung infection (pneumonia). To assess the efficacy of chest physiotherapy in the prevention of aspiration pneumonia in stroke patients.Materials and Methods: A quasi-experimental study was conducted with a sample size of 35 participants from C1 ward Agha Khan Hospital in Karachi City, Pakistan. The participants were selected via random sampling method. The inclusion criteria include patients of the C1 ward with a cerebrovascular accident, both male and female gender, with the age ranges from 45 to 63 years. All statistical analysis was done by using SPSS v. 19. The paired t test was used to evaluate the effectiveness of chest physiotherapy in a patient with aspiration pneumonia. The chest physiotherapy includes turning, postural drainage, percussion, vibration, deep breathing exercises, coughing, and suctioning were performed on a patient with aspiration pneumonia.Results: The results of this study show pre-treatment and post-treatment chest congestion, heart rate, and respiratory rate show that the P value is highly significant.Conclusion: This study concludes that chest physiotherapy seems to be effective in treating aspiration pneumonia in cerebrovascular accident patients.