Purpose: The purpose of this study was to identify the nutritional status and to compare nutritional indicators by caloric intake for intensive care unit patients, Methods: The participants for this descriptive investigation were 62 patients who were admitted to medical and surgical ICUs and started on enteral feeding. Data were collected in a tertiary hospital and the patients were followed for 7 days after enteral feeding was initiated. For analysis, patients who received 80% less calories than their required level were categorized as the underfed group and patients who received more than 80% to their required level, as the adequately fed group. Results: Compared to daily requirements, the prescribed calories and protein for patients overall were 77.39% and 64.75% respectively. The level of calories and protein given was less than their prescription. However, a comparison of the underfed group and the adequately fed group, showed that there was no significantly difference in albumin, prealbumin and transferrin. Only body weight was significantly different between the groups. C-reactive protein had a significant correlation with prealbumin and transferrin. Conclusion: Underfeeding is a common phenomenon among ICU patients. Nutritional indicators such as prealbumin, albumin and transferrin may not sensitive indicators to assess nutritional status of ICU patients.