Introduction: Surgery is a stressful situation which affects the metabolic and hormonal changes. Apart from surgical stress, anesthesia related procedures like Tracheal intubation, recovery from anesthesia, and post-operative pain can increase the stress induced hormonal changes. This study aims to find out the pattern of postoperative blood glucose response among non-diabetes patients receiving either general anesthesia or spinal anesthesia for their surgeries. Materials & Methods: An institution based, observational, cross-sectional study was conducted among 147 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: 66.0% of study population received general anesthesia and 34.0% received spinal anesthesia. In postoperative period, 41.5% of study population had their plasma glucose in pre diabetes range and 20.4% had their plasma glucose in diabetes range. Frequency of postoperative hyperglycemia (IFG + Diabetes) was 61.9%. 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.