Background & Aims: Increase in abdominal pressure can lead to the so-called intra–abdominal compartment syndrome (ACS) that is often observed during the first 24 hours after sever abdominal trauma and surgery. Measurement of the intra abdominal pressure through the bladder as a non-invasive measurement can provide a quick and accurate assessment of abdominal pressure changes. This study was performed to compare the diagnostic value of intra-abdominal pressure measurement through the bladder with that of physical exam in the diagnosis of surgery indication. Methods: This descriptive- analytical study was performed on patients with intra-abdominal compartment syndrome due to blunt abdominal trauma referred to Nemazee hospital, Shiraz, Iran. Tools for data collection included a check list consisting demographic information, and intra-abdominal pressure measurement instruments. Data analysis was done through SPSS software. Results: Of 100 patients with abdominal trauma whose abdominal pressures were measured, 28 ones had abdominal compartment syndrome of whom, 21 ones (75 percent) were referred to the operation room by physician. Among all patients who were sent to the surgery room, 5 patients (23.80%) were survived and all those who were not sent to the surgery room died. Mean diagnosis time of measuring abdominal pressure for detection of operation indication was significantly lower than that of physical exam (P<0.01). Age, sex, type of trauma and type of injury to internal organ had no significant relationship with the rate of abdominal compartment syndrome. Also, there was no significant difference between the two methods in finding surgery indication. Conclusion: Implementing education on methods of early diagnosis of intra-abdominal pressure increase for medical team especially nurses is one of the treatment priorities.