Background Practices of Do-Not-Resuscitate (DNR) orders show discrepancies worldwide, but there are only few such studies from Saudi Arabia. Objective: To describe the practice of DNR orders in a Saudi Arabian tertiary care ICU. Methods: This retrospective study included all patients who died with a DNR order at the ICU of King Saud Medical City, Riyadh, Saudi Arabia, between January 1 to December 31, 2021. The percentage of early DNR (i.e., ≤48 hours of ICU admission) and late DNR (>48 hours) orders were determined and the variables between the two groups were compared. The determinants of late DNR were also investigated. Results: A total of 723 cases met the inclusion criteria, representing 14.9% of all ICU discharges and 63% of all ICU deaths during the study period. The late DNR group comprised the majority of the cases (78.3%), and included significantly more patients with acute respiratory distress syndrome (ARDS), community acquired pneumonia (CAP), acute kidney injury, and COVID-19, and significantly fewer cases of readmissions and malignancies. Septic shock lowered the odds of a late DNR (OR = 0.4, 95% CI: 0.2–0.9; P = 0.02), while ARDS (OR = 3.3, 95% CI: 2–5.4; P < 0.001), ischemic stroke (OR = 2.5, 95% CI: 1.1–5.4; P = 0.02), and CAP (OR = 2, 95% CI: 1.3–3.1; P = 0.003) increased the odds of a late DNR. Conclusion: There was a higher frequency of late DNR orders in our study compared to those reported in several studies worldwide. Cases with potential for a favorable outcome were more likely to have a late DNR order, while those with expected poorer outcomes were more likely to have an early DNR order. The discrepancies highlight the need for clearer guidelines to achieve consistency.