Background: β-glucuronidase (βG) is one of the enzymes found in GCF that is involved in degradation of the ground substance and fibrillar components of host connective tissue. GCF βG activity might be a good indicator or predictor of periodontal disease activity. Material and method: 72 patients were enrolled in this study. These patients were divided into two groups of 36 each: Group 1: 36 diabetic patients with clinical and radiographic diagnosis of chronic periodontitis and Group 2: 36 non-diabetic patients with clinical and radiographic diagnosis of chronic periodontitis. All demographic data of these patients was obtained. Detailed clinical examination was carried out and subsequent data was recorded. Radiographic records were also obtained to evaluate the extent and severity of periodontal disease. A single test site was selected from each patient of Group 1 and 2. After light supragingival scaling, a standard volume of 0.6 µl GCF was collected. Collected GCF was immediately transferred to 150 micro litre of normal saline and sent to the laboratory for analysis. Results: Out of 36 patients in the diabetic group 19 were below 35 years of age. In the non-diabetic group 16 patients were below 35 years of age. It was seen that in the diabetic group 18 were males and 18 were females. In the non-diabetic group however 21 out of 36 patients were males. Mean GCF β-glucuronidase levels in the diabetic group with chronic periodontitis was 38.12. Mean GCF β-glucuronidase levels in the non-diabetic group with chronic periodontitis was 28.13. The standard deviation values of group 1 and group 2 were 15.53 and 12.86 respectively. Mean GCF β-glucuronidase levels in the diabetic group was significantly higher than the non-diabetic group with P-value of 0.00. Conclusion: Elevated levels of GCF β-glucuronidase were observed in patients with chronic periodontitis. The levels were even higher in diabetic patients. Key words: β - Glucuronidase, chronic periodontitis, diabetes, GCF