Background: Periodontal diseases are common chronic pathologies worldwide that affect periodontal tissues, which include the gingiva, periodontal ligament, radicular cementum, and alveolar bone. Matrix metalloproteinases (MMPs) are a large family of proteases involved in many cell-matrix and cell-cell signalling processes. Also matrix metalloproteinase-3 (MMP-3) or stromelysin-1 contributes to several pathologies. Hence; the present study was conducted with the aim of assessing MMP - 3 levels in gingival crevicular fluid in periodontal disease, healthy and after scaling and root planning. Materials & methods: A total of 60 subjects were enrolled in the present study. All the subjects were broadly divided into three study groups with 20 subjects in each group as follows: Group A: Clinically healthy controls with absence of any periodontal pathology, Group B: Subjects with clinical signs of inflammation, probing pocket depth (PPD) ≥5 mm and clinical attachment loss (CAL) ≥2 mm, with radiographic evidence of bone loss, and Group C: Subjects fulfilling the criteria of group B who were treated by scaling and root planing (SRP) only. All the patients were recalled in the morning and gingival crevicular fluid (GCF) samples were obtained using sterile micropipettes. All the samples were sent to laboratory where auto-analyzer and ELISA technique were used for assessing MMP-3 levels. Results: Mean MMP-3 levels among the patients of group A, group B and group C was found to be 0.39 ng/mL, 6.95 ng/mL and 2.96 ng/mL respectively. In the present study, significant results were obtained while comparing the mean MMP-3 levels among the patients of all the three study groups. Mean MMP-3 levels was highest among the patients of group C, followed by Group B and lowest for Group A. Conclusion: With increasing severity of periodontal destruction, there is concomitant increase in the concentrations of MMP-3 in GCF. Key words: Matrix metalloproteinase, Periodontal