Background and aims: Current diabetes treatments are based on blood glucose level monitoring. However, it is necessary to design another non-invasive reliable diagnostic method. In current study, we aimed to determine the relation between fasting blood sugar (FBS) and fasting salivary glucose. Methods: In this case-control study, 30 diabetic patients (case) and 30 non­diabetic individuals (control) referred to a military hospital in 2019 were studied. The correlation between FBS and fasting salivary glucose was evaluated with Pearson test. Results: The mean age of participants in control and case group was 55.4±2.8 and 63.7±2 years old, respectively. The mean FBS was 100.5±3.3 and 149.2±3.8 mg/dL in controls and cases, respectively, which were significantly different from each other (p<0.001). The mean fasting salivary glucose in the control group and the case group was 0.8±0.14 and 1.59±0.35 mg/dL, respectively, which was significant different in the two groups (p=0.038). Pearson analysis showed that there was a positive correlation between FBS and fasting salivary glucose (r=0.265, p=0.042). Conclusion: Fasting salivary glucose can be used as a noninvasive tool to control blood glucose in diabetics.