The oral cavity is said to be the mirror of systemic diseases and many systemic diseases may be identified on the basis of oral manifestation alone. With the advent of sensitive immunochemical assay, the composition profile of human salivary secretion has been expanding considerably. The establishment of range of normal values for a variety of intrinsic and extrinsic salivary components represents an initial step to use saliva as a diagnostic tool to assess oral health status. Diabetes mellitus is one such complex, multifactorial genetic disorder of unknown etiology characterized by increased insulin secretion. The oral manifestations in diabetic patients are decreased salivation, painful burning mouth and increased severity and prevalence of periodontal disease. The following study was conducted to estimate whole saliva constituents in patients with diabetes mellitus and to find a possible correlation with periodontal disease. The results obtained from the study showed a marked increase in the concentrations of the whole salivary parameters studied in the diabetic group with periodontal disease in comparison to the nondiabetic groups with and without periodontal disease.