Objective: To differentiate between Ancylostoma duodenale and Necator americanus by doing detailed microscopic study of head and mouth of these hookworms. Methods: All patients who had undergone upper gastro-intestinal endoscopy for a period of 2 years (2017 and 2018) were examined for the presence of parasitic worms. Results: Out of these patients who had undergone upper gastro-intestinal endoscopy 20 patients were found to have hookworms in duodenum. The head end and mouth of the hookworm is curvedlikea hook and hence it is identified as hookworm. Conclusion: The eggs of Necator americanus seen in stool examination are 60 to 70μm in length and are virtually indistinguishable from those of Ancylostoma duodenale. Hence detailed microscopic study of of head and mouth of these hookworms retreived out using biopsy forceps while doing upper gastro-intestinal endoscopy can only different between Ancylostoma duodenale and Necator americanus.