Introduction: Surgery is associated with increased stress response which results in sympathetic activations and the release of pituitary hormones that accelerate glycogenolysis and gluconeogenesis and result in stress hyperglycaemia. Recovery from anesthesia, and post-operative pain can increase the stress induced hormonal changes. Objective: To find out the pattern of postoperative blood glucose response among non-diabetes patients receiving either general anesthesia or spinal anesthesia for their surgeries. Methods: A Hospital based, Observational; Cross Sectional study was conducted at Department of Anaesthesiology, Gonoshasthaya Samaj Vittik Medical College, Savar, Dhaka, Bangladesh from January to December 2022. A total of 100 study subjects participated in the study was conducted among100 non diabetes patients who received either general or spinal anesthesia for their surgery. Data was analyzed using SPSS, version 20.0 for windows. Chi-Square test was used to show association between categorical variables and independent sample t-test was used to show mean difference among normally distributed continuous variables. All statistical tests were 2-tailed and a p-value of <0.05 was considered significant. Results: Total 100 patients included in our study. Mean age of the study population was 41.1±12.7 Years. 65.0% of the study population were in the age group of 31-60 years followed by 26.0% and 9.0% were in the age group of 18-30 years and ≥ 61 years respectively. 53.0% of them were female and 47.0% were male. 66.0% of study population received general anesthesia and 34.0% received spinal anesthesia. In postoperative period, 42.0% of study population had their plasma glucose in pre diabetes range and 20.0% had their plasma glucose in diabetes range. Frequency of postoperative hyperglycemia (IFG + Diabetes) was 62.0%. Mean postoperative plasma glucose was significantly higher among study population who received general anesthesia. Increasing age, female gender, overweight, obesity, hypertension and hypothyroidism was significantly associated with high risk of postoperative hyperglycemia. Conclusion: There is high prevalence of postoperative hyperglycemia. The frequency of postoperative hyperglycemia was significantly high among those who received general anesthesia than those who received spinal anesthesia.