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.