Obesity can be considered as a chronic disorder of energy imbalance, in which a long-term excess of energy intake over expenditure leads to the storage of that excess energy as adipose tissue. This study aimed to investigate whether childhood obesity in primary school girls affects the levels of measured hormones, peptides and neurotransmitters as well as their cognitive function and to study the relationships between the measured biochemical parameters and cognitive function in those girls. Childhood obesity represents a serious health problem. Obesity could induce a disturbance in the levels of the vital hormones especially GH and IGF-1. In addition, obese status in girls at this young age is associated with worse cognitive function which reflects the impact of obesity on educational achievement and learning ability in these girls. This may afford an aid in manipulating childhood obesity and developing strategies for treatment of this disease.