Background: A high number of patients with Periodontitis may have undiagnosed diabetes mellitus (DM). Diabetes is an associated risk factor for chronic periodontitis and has several other oral symptoms including dry mouth and oral infection. Expanding the role of the dentist may prove to be an efficient method of early detection and management of diabetes. Aim: The purpose of the present study was to evaluate whether blood oozing from gingival crevice during routine periodontal examinztion can be used for determining glucose levels. Materials and Methods: A total of 120 male/female patients with Chronic Periodontitis in the age group of 30 years and above were selected and divided into three groups i.e. Control Group (Plasma glucose level), Test Group 1 (Finger capillary blood) and Test Group 2 (Gingival crevicular blood). Blood glucose measurements were made using gingival crevicular blood and finger capillary blood using glucose self monitoring device (Accu-Chek Active) and at the same time venous blood was collected for measurement of serum (plasma) glucose. Data obtained were statistically analyzed using Paired t-test (p), and Pearson's correlation test (r). Results: The results revealed a strong correlation between (a) gingival crevicular blood and finger capillary blood (r = 0.999; P