Background: Ghrelin is well recognized as a key factor in regulating appetite and energy homeostasis. The aim of the present study is to characterize the plasma ghrelin concentrations in children with type 1 diabetes at the time of diagnosis and to determine the effect of metabolic control after insulin therapy on circulating ghrelin levels. Also, the relationship between the simultaneous blood glucose concentrations and fasting plasma ghrelin concentrations was explored. Material/Methods: This prospective study assessed the changes in pre-prandial plasma ghrelin levels after treatment of type 1 diabetes with insulin. Results: The study comprised 19 children with new onset diabetes mellitus. Mean plasma ghrelin levels declined by 29% in diabetic children post insulin treatment (p=0.007). There was a significant correlation between plasma ghrelin and body mass index (BMI) in children with type 1 diabetes at diagnosis (r=-0.54), but not at follow up. The difference in ghrelin at diagnosis and at 3 month follow up demonstrated an inverse relationship to difference in plasma glucose (r=-0.48). Conclusions: Plasma ghrelin concentrations could be suppressed in untreated type 1 diabetic children by improved glycemic control following insulin replacement. © Med Sci Monit, 2007.