Background:Like other large abdominal procedures, upper abdominal surgeries can weaken respiratory muscles in the postoperative phase and cause mechanical alterations in the lungs. Patients may experience significant decreases in respiratory function following these procedures, depending on the presence of previous conditions. Purpose: This study was conducted to assess the impact of the active cycle of breathing techniques versus autogenic drainage for improving the pulmonary functions and arterial blood gases of upper abdominal surgery patients. Subjects and methods: Sixty patients (38 males and 22 females) underwent upper abdominal surgeries (abdominal exploration)and aged from 40-55 years were selected at random from Al-Ahrar learning hospital one day post-operative and divided into two equal groups in number, each group involved 30 patients. Patients in group (A)was given active cycle of breathing techniques in addition to early ambulation while patients in group (B)was given autogenic drainage in addition to early ambulation intervention. Patients in both groups were examinedat baseline and following 7 days of treatment (post-training) to measure forced expiratory volume in 1 second (FEV1) using pulmonary function test (PFT) and PCo2 using ABG lab testing. Results: The results of this study showed that there was significant increase in both forced expiratory volume in 1 second (FEV1) with P-value = 0.11 and significant decrease in PaCo2 with P-value = 0.11 for both groups of the study.No significant difference was observed amongactive cycle of breathing techniques and autogenic drainage. Conclusion: Both techniques had the same effect in improving pulmonary functions and arterial blood gases in post upper abdominal surgeries patients.