A bidirectional relationship has been reported between diabetes mellitus and periodontitis. The present study aimed to estimate salivary fructosamine in diabetic and non-diabetic individuals with healthy and diseased periodontium and to measure its changes after non-surgical periodontal therapy. Another aim was to identify the cut-off value of salivary fructosamine to diagnose diabetes mellitus and to correlate it with glycated hemoglobin. Salivary fructosamine and HbA1c were assessed in periodontally healthy individuals and periodontitis patients (n = 60 in each group). Both groups comprised of equal number of patients with and without diabetes mellitus. Salivary fructosamine estimation was repeated 4weeks after non-surgical periodontal therapy in periodontitis patients. HbA1c and Salivary fructosamine were significantly higher in the periodontally diseased compared to the healthy group. Significantly higher values of these biomarkers were noticed in diabetic patients with periodontitis compared to the non-diabetic group. Periodontal therapy significantly reduced salivary fructosamine in both diabetic and nondiabetic periodontitis patients. A significant positive high correlation was noticed between salivary fructosamine and HbA1c (r = 0.76). The cut-off value of salivary fructosamine was found to be 68µg/mL with 95% sensitivity, 81.67% specificity, 83.82% positive predictive value, and 94.23% negative predictive value. Periodontitis can contribute to glycemic control and periodontal therapy can bring about improvement in glycemic status. Salivary fructosamine could be used as an alternate glycemic biomarker and its advantages over HbA1c include simple and non-invasive collection of saliva and it can provide intermediate glycemic status. 2020/11/038496.