Background: Use of checklist in evaluation of trauma patients has been a critical component of improving the care process and reducing medical errors and increasing patient's quality of life. We aim to assess the impact of the modified World Health Organization Trauma Care Checklist (WHO TCC) on the management of pain, complications, mortality and patient satisfaction in trauma patients. Methods: This was a randomized control trial (RTC). Trauma patients referred to the trauma center and met the eligibility criteria were randomly assigned into three study groups. Group 1 were patients who received trauma care without using the WHO checklist, and only by the standard of care. Group 2 were patients who received trauma care according to the WHO's checklist, and group 3 were patients received trauma care according to the WHO's modified checklist. We used independent t-test and chi-square tests to assess the association between the study variables with checklist groups. The significance level of tests was set for p-value less than 0. 05. Results: We observed patients’ level of pain, Injury Severity Score (ISS), Glasgow Coma Criterion (GCS) and patient satisfaction significantly improved across the checklist groups, but more so in the modified checklist group (P less than 0. 001). Similarly, findings reveal significant relationships between all clinical characteristics of the patients and checklist groups, except for a CT Scan of the spinal cord. We were unable to establish any significant associations between the checklist groups and the majority of the selected trauma care process measures, except for missed injury (p = 0. 001). Conclusions: Both the WHO TCC and the WHO modified checklist, in the initial assessment and during the treatment and care processes, enhance patients’ clinical outcomes. However, patients in the modified checklist compared to WHO TCC reported a higher level of satisfaction. Implications and future directions are discussed.