Introduction The objective of this study is to assess the periodontal inflamed surface area (PISA) and its relationship with glycemic control in type 2 diabetes with and without periodontitis. Materials and methods A study was performed on 60 out-patients (males and females) reporting to the Department of Periodontics, Rajah Muthiah Dental College and Hospital and the Diabetic Clinic, Rajah Muthiah Medical College, Annamalai Nagar, Chidambaram, Tamil Nadu. The age of the study subjects ranged from 40 to 60 years. Patients having HbA1c levels > 7 mg/dl were diagnosed as type 2 diabetes mellitus and were enrolled in the study. The selected patients were divided into two groups of 30 patients each, with at least eight remaining teeth present: Group I - Diabetic patients with periodontitis (test) with probing pocket depth (PPD) of 3 to 10 mm and bleeding on probing (BOP), and Group II - Diabetic patients without periodontitis (periodontally healthy as control) with PPD not exceeding 3 mm and limited BOP. Subjects were excluded if they were under systemic antibiotics 3 months prior and during the study and if they have undergone periodontal treatment 6 months prior to the study. Results When HbA1c increased, the PISA values also increased in type 2 diabetic patients with and without periodontitis. Conclusion The cross-sectional clinical study reveals that there is a linear association between diabetes and PISA in type 2 diabetic patients with and without periodontitis. How to cite this article Devi S, Murugappan S, Swaminathan M, Ilangovan K, Mangalekar SB, Kannaiyan A. Assessment of Periodontal Inflamed Surface Area and Its Relationship with Glycemic Control in Type 2 Diabetes. J Health Sci Res 2016;7(1):6-11.