Background: The management of trauma patients is often difficult. The American college of surgeons suggests using advanced trauma life support (ATLS) measures. ATLS is regarded as the gold standard for the resuscitation of cases with acute life threatening injuries. Objectives: To assess the change in base excess (BE) values and central venous pressure (CVP) one and six hours after injection of 1000 cc normal saline in trauma patients admitted to the ICU. Patients and Methods: According to the inclusion and exclusion criteria, patients were randomly selected to participate in the project. Inclusion criteria included trauma patients admitted to the ICU with a CVP line and who had indication for hydration. In trauma patients, at the zero time period, BP, PR, RR and CVP were measured, and a blood gas test was used to assess Hb, pH, BE, PO2, HCO3 and PCO2. Then 1000 cc of normal saline was injected, and after one and six hours, the same values were re-evaluated. Results: The mean age of the patients was 38.1 ± 3.9 (range 15 - 60). The mean duration of hospitalization was 7.4 ± 4.4 (range 1 - 21) days. The mean ISS for these patients was 14.33 ± 5.3. BE changes in both groups of patients, based on Hb primary division, showed a significant difference (P ≤ 0.05). The results showed that there was no significant relation between the measured ISS and the changes in base values (P ≥ 0.05). Conclusions: According to our results, the infusion of one liter normal saline will cause a statistically significant decrease only in BD, after one hour, in patients withmoderate to severe ISS. The changes in SBP, PR, CVP and also pH, HCO3 and Hb were not statistically remarkable