Background: Hyperglycemia on admission among COVID-19 may affect the patient outcome. Objective: To determine the effect of admission hyperglycemia on outcome among COVID-19 patients. Methodology: It was a cross-sectional analytical study in which 421 COVID-19 patients were admitted with high blood sugar levels (BSR>180mg/dl) to the High Dependency Unit, Sir Sadiq Abbasi Hospital, Bahawalpur, from April to May 2021 were included. Preexisting diabetes status was confirmed on the basis of history taken from the patients. Patients were divided into two groups on basis of BSR, moderate hyperglycemia (180-299mg/dl) and severe hyperglycemia (300-450mg/dl). The primary outcome was taken as an increase in oxygen demand leading to shifting of the patient to ICU for Non-Invasive Ventilator (NIV) support or a decrease in oxygen demand leading to discharge home. Results: Among 421 COVID-19 patients; 349 (83%) patients had moderate hyperglycemia and among them, 172 (49.4%) were shifted to NIV, and 177 (50.6%) patients were discharged after improving. Seventy-two patients came out to have severe hyperglycemia out of which 61 (84.3%) were shifted to NIV and 11 (15.3%) patients were discharged home (p-value = 0.01). Among 83 patients who were shifted to NIV, 22 (26.5%) were diabetic and 61 (73.5%) were non-diabetic and had risk factors other than diabetes. Conclusion: Hyperglycemia on admission is a strong predictor of poor outcomes regardless of the previous history of diabetes and other confounders.