Active Cycle of Breathing Technique (ACBT) is a breathing exercise technique which used to remove secretions from the lungs. So this study aimed to assess effect of active cycle of breathing technique on patients' outcomes regarding abdominal trauma. A quasi experimental design was used.

Setting: This study was carried out in trauma intensive care unit at Assuit University Hospital.

Sample: 60 adult critically ill patients with abdominal trauma.

Tools: Patient's assessment sheet and abdominal trauma severity assessment tool and Patients respiratory parameters and abdominal pain evaluation sheet.

Main results: There were 65% males and 35% females. Mean Age was 37.56 ± 11.34 for study group and 36.50 ± 11.12 for control one. There was a reduction in the respiratory rate in study group after application of ACBT with statistically significant differences between both groups. There were statistical significance differences regarding PaO2, PaCo2, SaO2 between both groups at 5th day with P. value (0.041, 0.002, 0.007) respectively. Statistical significance differences between before and after intervention regarding abdominal pain was found in both groups.

Conclusion: Active cycle of breathing technique is a vital procedure for abdominal trauma patient to improve outcomes. Recommendations: ACBT can be used to abdominal trauma patients in ICU to improve respiratory parameters, so that oxygen needs are met.