The aim of this study was to determine the relationship between periodontal disease and the blood glucose level among type II non-insulin dependent diabetic mellitus (NIDDM) subjects. Forty subjects, 20 in each group, of healthy and diabetic subjects, ages ranged 20-70 years, were examined at King Saud University, College of Dentistry. Clinical examination included frequency of oral hygiene practices, periodontal status by using the Community Periodontal Index of Treatment Needs (CPITN), fasting blood glucose level (FBGL), and random blood glucose level (RBGL). Unstandardized orthopantomograms (OPGs) were taken for radiographic findings. The number of missing teeth (tooth loss) was assessed from the radiographs. The results showed that periodontal disease severity was high among diabetic subjects. Diabetic subjects brushed less frequently, and they had a higher blood glucose level than healthy subjects. The mean CPITN score was compared with mean blood glucose level and the severity of periodontal disease. There was a steady increase in blood glucose level with increase in CPITN scores, i.e., CPITN score 13.5 to 19.12 corresponded with 142 mg/dl and 173.2 mg/dl FBGL, and 184.2 and 199.12 mg/dl RBGL among diabetic subjects. The study indicated that diabetic subjects should improve their oral hygiene practices and control of blood glucose levels should be emphasized. Further studies are needed among diabetics and healthy subjects from the general population with better sampling techniques and a larger sample size.