Background: Stress hyperglycemia is common among critically ill patients admitted in the intensive care units (ICU), affecting 17-68%of patients within the first 48 hours of admission. Long-term stress hyperglycemia is linked to poor clinical outcomes and increases mortality. The burden and outcomes of stress hyperglycemia in critically ill patients is unknown in Tanzania. Methodology: Prospective short-term cohort study was conducted at Muhimbili National Hospital for 6 months. Adult critically ill patients in medical and surgical ICU were recruited consecutively. On admission, HbA1c and RBG were checked. FBG/RBG was tested daily until discharge or death. Stress hyperglycemia was defined as FBG≥6.1mmol/l or RBG of 140mg/dl (7.8mmol/L) or more observed during ICU admission. Length of stay and ICU mortality in one month of follow-up were recorded. SH proportion is reported as percentages. Predictors of SH were analyzed using logistic regression. P value <0.05 was considered statistically significant. Kaplan Meier’s mortality curves were used to compare the mortality of patients with SH to those without. Results: A total of 270 patients were enrolled, among them 120/270(44.4%) developed SH. These patients were largely male (58.2%) with a mean age of 48.2±17.8years. predictors of SH were having comorbidities and the use of steroids. Stress hyperglycemia increased the risk of staying in the ICU for ≤ 5 days by 2 folds aOR (95%CI), 2.416 (1.261-4.629) P=0.008. Steroid use reduces the risk of SH by 67% aOR (95%CI), 0.326 (0.167-0.636) P=0.001 and by 78% for patients with other comorbidities aOR (95%CI), 0.2196(0.097-0.497) P<0.001. Conclusion: The incidence of stress hyperglycemia is high in ICU patients as evidenced in this study. Duration of ICU stay, comorbidities, and steroid use was significantly associated with stress hyperglycemia. Stress hyperglycemia contributes to a higher mortality rate among critically ill patients.