Methods: In the current cross sectional study, 580 children hospitalized in the Division of Pediatric Infectious Diseases at Imam Khomeini Hospital were recruited through the census method. To collect the relevant data, a demographic information questionnaire, the household food security survey module (HFSSM), and tools such as a tape measure and a weighing scale were used. Within these indices, weight - for - age indicated being underweight, weight - to - height represented thinness, and weight - for - age showed short stature. The data, in terms of descriptive and inferential statistical tests were analyzed with SPSS version 16. Results: The results revealed that out of the 580 children examined, 192 (33.1%) were moderately underweight, 166 (28.6%) had moderate thinness, and 167 (28.8%) had a moderate short stature. In total, 453 (78.1%) children had food security. Furthermore, a statistically significant relationship was observed between the causes of hospitalization and being underweight or thin and food insecurity (P < 0.001). Conclusions: Given the statistically significant relationship between nutritional status, food insecurity, and causes of hospitalization in children, it is necessary to take appropriate interventions to promote nutritional st

Keywords: Nutritional Status, Food Insecurity, Children, Infectious Diseases