OBJECTIVE Periostin is a matricellular protein highly expressed in periosteum, periodontal ligament and is essential for tissue integrity and maturation. It plays a role in collagen fibrillogenesis and is downregulated in periodontal disease. Biostimulation utilizing low-level laser therapy (LLLT) influences periodontal ligament fibroblast proliferation. This study was conducted with the objective of estimating periostin levels in chronic periodontitis (CP) patients following LLLT as an adjunct to root surface debridement (RSD). METHODS Thirty periodontally healthy participants (Group I) and sixty CP participants were recruited. Based on the therapeutic intervention, CP patients were allocated to either RSD (Group II) or to RSD with LLLT (Group III) group. Clinical parameters and gingival crevicular fluid (GCF) periostin levels were assessed at the baseline and at the 3rd month. RESULTS Periostin levels were significantly lower in CP patients when compared to healthy individuals at the baseline (P < 0.01). Following nonsurgical periodontal treatment (NSPT), periostin levels significantly increased in both Group II and III, when compared to baseline values (P < 0.001). Comparison of mean periostin levels between both the treatment groups showed a significant increase in LLLT group than RSD at the 3rd month (P < 0.05). CONCLUSIONS Within the limitations of the present study, LLLT application was found to have additional benefits over RSD with respect to clinical periodontal parameters and GCF periostin levels. Moreover, periostin may be used as a possible biomarker to evaluate the outcome following NSPT.