Oral cancer is the sixth most common cancer throughout the world and is a crucial issue in regions where tobacco habits, in the form of chewing and/or smoking, with or without alcohol intake, are common. Squamous cell carcinoma is the cause for 95% of oral cancers and is associated with avoidable aetiological risk factors. The most successful means to enhance the survival and reduce morbidity, damage, duration of treatment and hospital cost is the detection of oral cancer at an early stage. It is essential to study marker levels in patients with oral precancer who are at a high risk of developing oral cancer. The present study was carried out to evaluate usefulness of serum Total Sialic Acid (TSA) and serum Lipid-Bound Sialic Acid (LSA) as markers of oral submucous fibrosis and oral cancer. Study consisted of 60 patients and 30 controls. There were 3 study groups, Group I control, Group II OSMF, and Group III oral cancer consisting of 30 patients each. Serum of all the patients in the control group and study groups were collected and stored at -20 oC until analyzed. Levels of serum TSA and LSA were estimated spectrophotometrically. The results also demonstrated that the assessment of TSA and LSA by simple, in-expensive and reproducible methods can provide significant clinical information about the extent of malignant disease and can differentiate between patients with oral precancer and oral cancer.