Statement of the Problem: Reducing the patients' stress can prevent, or at least, limit the increase in blood glucose level.Purpose: The study compares the effect of propofol and midazolam on blood glucose level in the patients undergoing dental implant surgery. The effect of pre-operational stress on blood glucose level during the surgery is also evaluated.Materials and Method: This prospective randomized clinical trial recruited 33 patients undergoing dental implant surgery and divided into two groups. Conscious sedation was performed by midazolam in one group and with propofol in another group. The pre-operational stress was scored and the blood glucose level was measured in 4 different stages; before the operation, two minutes after the local anesthetic injection; thirty minutes after the onset of operation and at the end of the operation. The results were analyzed by employing ANOVA and Pearson test. The p Value was adopted 0.05 and the confidence coefficient was assumed 95%.Results: The average levels of the blood glucose in midazolam and propofol group were 93.82 mg/dl and 94 mg/dl before the operation which displayed a meaningful increase of blood glucose level in both groups as the operation went on. The values were 103.76 mg/dl for midazolam and 108.56 mg/dl for the propofol group (p< 0.05) at the end of the operation.No statistically significant difference was found in the average blood glucose level between two groups in the different stages of the operation (p= 0.466). The Pearson correlation coefficient test revealed a higher increase in the blood glucose level in the patients with a higher pre-operational stress score (r= 0.756, p< 0.001).Conclusion: Based on the results yielded by this study, patients who receive venous sedation, either by midazolam or propofol, experience increase in the blood glucose level while undergoing an operation. No statistically significant difference was detected between midazolam and propofol.