Objective: The objective of this study was to determine the efficacy of curcumin in combination with intralesional dexamethasone with hyaluronidase in the treatment of oral submucous fibrosis (OSF). Methods: This randomized, double blind, parallel design, clinical trial was conducted at B.P. Koirala Institute of Health Sciences, Nepal. Thirty-four patients with clinically diagnosed OSF were randomized into two groups (17 participants in each) with baseline treatment of intralesional dexamethasone with hyaluronidase for 6 weeks for the both. Curcumin (2gm/day) was provided to Group A (Test) and Group B (Control) received placebo. Interincisal mouth opening, tongue protrusion, cheek flexibility and visual analogue scale (VAS) scoring of burning sensation of oral mucosa was recorded at baseline, 6, 8 and 12 weeks follow-up and independent t-test was used to compare the improvements in two groups. Results: On comparing the 6 weeks and baseline values, in Group A and B the mean difference in mouth opening was 8.82±1.33 mm and 5.53±1.17 mm respectively (p<0.001), in cheek flexibility was 2.94±1.02 mm and 1.94±1.24 mm respectively (p=0.02) and in tongue protrusion was 6.23±1.48 and 3.65±1.37 mm respectively (p<0.001). The findings were consistent in the 8 weeks follow-up. In 12 weeks follow-up, on comparing with the baseline values, in Group A and B, the mean difference in mouth opening was 8.71±1.16 mm and 5.35±1.22 mm respectively (<0.001), ), in cheek flexibility was 2.81±1.01 mm and 1.76±1.35 mm respectively (p=0.02) and in tongue protrusion was 6.06±1.48 and 3.35±1.50 mm respectively (p<0.001). Both the arms showed 100% improvement in burning sensation in 6, 8 and 12 weeks follow-up. Conclusion: Curcumin in combination with intralesional dexamethasone with hyaluronidase is efficacious in the treatment of OSF.