Aims: Odontogenic lesions comprise a complex group of lesions of diverse histopathologic types and clinical behaviour. These tumours are characterized by the presence of secretory material. Some of these secetory materials may show calcification. The secretory materials have been attributed to a wide range of material including enamel, dentin and cementum or bone, however the exact nature is still unknown. Methods like IHC though available are expensive, technique sensitive and questionable in certain circumstances. To identify the nature of secretory material in selected odontogenic tumours by using a histochemical stain called modified Gallego’s stain using hard tissues of the tooth as the control. Methods: The study will constitute a total of 12 histopathological proven cases (3 cases each) of various odontogenic tumours like adenomatoid odontogenic tumour, calcifying epithelial odontogenic tumour, calcifying odontogenic cyst and cemento-ossifying fibroma containing secretory material as identified in heamatoxylin and eosin stained sections. The tissue sections from the above cases will be subjected to a histochemical stain called as modified Gallego’s stain using hard tissues of the tooth as the control. Results: Adenomatoid odontogenic tumour, calcifying epithelial odontogenic tumour, calcifying odontogenic cyst we found dentinoid like material and cemento-ossifying fibroma we found bone and cementum like material.