The present study intends to compare and correlate serum & salivary glucose level in healthy & diabetic individuals. A total of 500 subjects were examined, of which 429 were healthy & 71 were confirmed diabetics. Post–prandial blood and salivary samples were analyzed. Mann-Whitney test using Pearson correlation was applied, which was statistically significant (P < .001). To conclude, glucose concentration in saliva is higher in diabetics than in healthy individuals. Moreover the changes in serum glucose concentration are followed by the changes in salivary glucose concentration. Thus saliva can be used as an adjunct diagnostic tool in diabetes mellitus.