Objective: Anaemia occurs very commonly in hookworm infection. Many studies have also shown the presence of anaemia in hookworm infection. But so far detailed study was not done to know about the absence of anaemia in the early stage of hookworm infection. Hence a detailed study was done to know about the absence of anaemia in the early stage of hookworm infection diagnosed by doing upper gastro-intestinal endoscopy in our institute. Methods: A study of 1100 patients who had undergone upper gastro-intestinal endoscopy for a period of four and half years from May 2009 to October 2013 was carried out in our institute. In all these 1100 patients, the first and second part of duodenum were carefully examined to find out the presence of hookworms. In all the patients who were found to have hookworms in duodenum, investigations were done to know about the presence or absence of anaemia and eosinophilia except in the very few patients who were lost for follow up. The results were found as given below. Results: Out of these 1100 patients, as many as 18 patients were found to have hookworms in duodenum while doing upper gastro-intestinal endoscopy. But 4 patients were lost for follow up. The remaining 14 patients were taken into consideration for our study. Out of these14 patients, 9 patients had anaemia but 5patients did not have anaemia. Absence of anaemia indicates minimal loss of blood due to very low burden of hookworms which can occur only in the early stage of hookworm infection. Hence absence of anaemia is suggestive of early stage of hookworm infection. But majority of the patients who did not have anaemia due to early stage of hookworm infection (4 out of 5patients) had significant eosinophilia. Conclusion: Hence, in the early stage of hookworm infection eosinophilia alone can be present without the presence of anaemia. Hence eosinophilia is an extremely important indicator of early stage of hookworm infection which is not associated with anaemia. Hence upper gastro-intestinal endoscopy should be done to confirm the presence of hookworms in all patients with eosinophilia even when there no anaemia in tropical countries.