Background: Open heart surgery patients usually develop pulmonary complications such as atelectasis, pneumoniain early postoperative period. Literature reported that to prevent or reduce these complications we can use Positive Expiratory Pressure (PEP) therapy techniques with Conventional Physiotherapy Treatment (CPT). Methods: The study design was Randomized Pilot Study. 20 patients included (n=20), 10 patients in each group, Control and Interventional group. Control Group received CPT while Interventional Group received CPT with Blow Bottle PEP (BBPEP) on Post-operative Day (POD) 1 and 2, twice a day and oxygen saturation noted pre and post treatment. Unpaired-t test was used. Result: The therapist made cost-effective and easily BBPEP therapy showed a short-term improvement in oxygen saturation with significant p-value 0.03. Conclusion: BBPEP device is effective in improving oxygenation in early POD i.e. on 1st and 2nd after open-heart surgery.