Context:Oral submucous fibrosis (OSMF) has a multifactorial etiology. Recent studies have shown that there is an increased level of fibrinogen degradation products (FDP) in plasma of OSMF patients suggesting its possible role in etiopathogenesis of OSMF.Aims:To detect the presence of FDP in the plasma of betel nut chewers with and without OSMF and in normal subjects without any habits, to correlate these levels with respect to the clinical and histological grading of OSMF and whether it can be used as a nonsurgical diagnostic aid in detection of suspected OSMF cases.Materials and Methods:Study comprised of 35 cases of betel nut chewers with OSMF, 10 patients with betel nut chewing habit but having apparently normal oral mucosa, and 10 normal patients without any habits. The patients were evaluated for plasma FDP levels.Results:All the betel nut chewers with OSMF showed the presence of plasma FDP. However, controls and subjects with habit, but without OSMF did not show FDP in the plasma. Spearman's rank correlation was used to find the association between the clinical and histological grades and it was not statistically significant (P = 0.910) and the correlation being 0.020.Conclusion:Since only those patients with OSMF have showed the presence of FDP in plasma, we suggest that our test can be utilized as a nonsurgical diagnostic aid in suspected OSMF patients.