Aim: The current study's aim was to assess gingival crevicular blood as a noninvasive method to measure blood glucose levels. Materials and methods: The current study comprised a total of 50 patients who had been diagnosed with chronic periodontitis and age was ≥30 years old. The study's procedures were carried out after receiving informed consent. For finger capillary blood collection method, a sterile lancet was used to prick the finger and a drop of blood was taken, for gingival crevicular blood collection method, blood was taken from the gingival margin of the chosen site, and for venous blood collection method with the aid of a disposable syringe, a venous blood sample was taken from the patient's antecubital fossa for determining blood glucose levels. One-way analysis of variance (ANOVA) was used to examine the differences between the three methodologies’ significance, and Karl Pearson's correlation (r) was used to determine their correlation. Results: The maximum glucose level was found in venous blood (187.78 ± 18.23), followed by finger capillary blood (181.88 ± 21.67) and gingival crevicular blood (169.04 ± 11.24). And there was no significant difference between the different blood collection methods (p > 0.05). The positive significant correlation was found between gingival crevicular blood and finger capillary blood (r = 0.912, p < 0.001). Correlation with gingival crevicular blood and venous blood showed a positive correlation (r = 0.898, p < 0.001). Correlation between venous blood and finger capillary blood also showed a strong positive correlation (r = 0.988, p < 0.001). Conclusion: In conclusion, the findings of the current study suggest that blood drawn from the gingival crevicular during a clinical examination may be a great source for glucometric analysis. The gingival crevicular blood may show to be a promising technique for routine dental office screening for diabetes mellitus in periodontal patients, even if capillary/venous blood samples used for diabetes mellitus screening are the gold standard. Clinical significance: Oral health is crucial for the early detection of many systemic disorders. As a result, dentists are crucial in the screening for systemic disorders. One of the prevalent chronic disorders is diabetes. Any systemic disease that is detected early enough can avoid long-term problems.