To evaluate and compare the serum IgG level in Diabetic and Non-Diabetic patients of RCDSR having Periodontitis”  In this study, humoral immune responses were assessed in 60 patients. 15 patients each belonging to the four groups diabetic with periodontitis, diabetic without periodontitis, non-diabetic with periodontitis and non- diabetic without periodontitis (control) were analysed for the quantitative estimation of serum immunoglobulins G by Turbidometric Immunoassay. The serum of the Diabetic and non-diabetic patients was collected and Immunological assay was done by Turbidometric method by using Quantia IgG Turbidometric immunoassay for estimation of Immunoglobulin IgG in human serum, (Tulip diagnostics [P] Ltd., Goa, India). The data thus obtained were compared to the level of immunoglobulin found in clinically healthy gingiva. We estimated the sugar level by checking the Random Blood Sugar level by Glucose Test Kit based on end point and kinetic assay and also HbA1c percentage of the candidates, by using Nyco Card Reader. All the patients of Group A (Diabetic with Periodontitis) showed significant (P < 0.01) increase in serum IgG level as compared to controls (Group D- Non Diabetic, Non Periodontitis). Group B showed significance of p = 0.006. Group C showed significance of p = 0.044 and Group D showed significance of p < 0.000. With an increase in HbA1c percentage serum IgG showed significant (P < 0.01) increase.  In the present study, the concentrations of the IgG in serum of diabetic and non-diabetic patients were found to be significantly high, when compared to the healthy subjects who had neither diabetes nor periodontitis. It was concluded that the IgG level in the serum of both diabetic and non-diabetic subjects with periodontitis were found to be significantly higher than that of healthy subjects. This study goes in accordance with the concept that the humoral immune response plays an important role in the pathogenesis of periodontal disease in diabetics. The significantly higher levels of immunoglobulin in the gingival tissues may be playing as a protective mechanism against the increased bacterial load in diabetic subjects. It may be postulated that increase in concentration of immunoglobulin in the diabetic group may be representing an enhanced response to diabetic state in periodontitis. The observations of the present study conclude the possible relationship associated with increased rate of tissue destruction in diabetic patients with periodontitis. The present study indicates that poor glycemic control may be associated with the increase in serum antibodies. Elevated antibody level explains why poorly controlled diabetes exacerbates periodontal disease.