Purpose: The purpose of this study was to describe the differences between early and delayed enteral nutrition on nutritional intake. Methods: A pilot cohort study was conducted with 45 critically ill adult patients who had a primary medical diagnosis. Energy prescribed and received were collected during the four days after initiation of enteral nutrition. Adequate feeding was defined as the energy intake more than 90% of required energy. Results: A total of 23 patients (52%) were received early enteral nutrition (within 48 hours of admission). Energy intake of early enteral nutrition was less than intake of delayed enteral nutrition during the four days of the study. Although the difference on day one was significantly greater than the differences on day two, the differences on day two were not different from days three or four. No statistical differences in the adequacy of nutritional intake were found between patients in the early and the delayed group. Conclusion: In critically ill patients receiving early enteral nutrition, more aggressive administration from the beginning will improve the nutritional intake. Additional studies including a large multi-centre, randomized clinical trial are recommended.