Abstract: Abstract： Objectives To assess the usefulness and reliability of the gingival crevicular blood for estimating the glucose level during routine periodontal examination. Methods Thirty patients with chronic periodontitis were selected (21 men and 17 women). Blood sam?ples were collected from gingival crevicular blood and fingerstick capillary blood respectively and detected with blood glucose meter. Results Measurements from gingival crevicular blood samples ranged from 4.8 to 16.7mmol/L with a mean of 7.77±3.43mmol/L and glucose measurements obtained from fingerstick capillary blood ranged from5.0 to 17.0mmol/L with a mean of 7.94±3.67mmol/L. Data were analyzed using a Pearson’s corre?lation coefficient and paired t-test. Paired t-test (P=0.114) showed no significant difference while a r-value of 0.990 showed very strong correlation between gingival crevicular blood and fingerstick capillary blood, which was statis?tically significant (P<0.001). Conclusion The data from this study has shown that gingival crevicular blood may serve as a potential source of screening for diabetes during routine peri?odontal examination in populations with an unknown history of diabetes mellitus.