Oral cancer is one of the most common cancers in India. It's also associated with poor survival rate. Early diagnosis is the only way of reducing the high morbidity and mortality associated with it. However, most often there is delay in its diagnosis. Several adjuncts have been developed to aid in the diagnosis of cancer in its pre-cancerous and early stage. Chemiluminescence is one of the newly developed adjuncts, which is still in its infancy. This article reviews chemiluminescence technique and its applications in oral cancer diagnosis.