At present, there is a lack of scientific evidence on toxicity from low-level mercury exposure in children. Despite the debate over the safety of dental amalgam fillings, amalgam is still widely used to restore posterior teeth in pediatric dentistry.  Although, children could be at greater risk to harm from low-level exposure due to their developing nervous systems. Hence, this research was carried out to define some potential health effects from dental amalgam on children's health. Children were selected from those attending the Pedodontic clinic, Faculty of Dentistry, Tanta University. They were subjected to clinical examination, neurobehavioral and intelligence quotient (IQ) assessment, urinary mercury level, serum; malondialdehyde (MDA), reduced glutathione (GSH), zinc (Zn), and gamma amino butyric acid (GABA) measurement. The present study revealed thatthe mean urinary mercury level was significantly higher in the amalgam group (8.15+0.99μg/L) than in the control group (3.53+0.94 μg/L). The urinary mercury level in children who had more than two amalgams or had duration 2 years or more was higher than children who had less than 2 amalgams or had duration less than 2 years. There was no difference in IQ between children with and without amalgam fillings. The children who had amalgam restoration were estimated to be more withdrawn, more anxious/depressed, and to have more social problems than the control group. Furthermore, greater attention problems and delinquent/rule-breaking problems were recorded in the children with amalgam filling than in the control children. Also there was significant increase of serum MDA level and significant decrease of serum levels of GSH, Zn, and GABA levels in amalgam group than the control. These changes were more evident in children who had more than 2 amalgams or had duration 2 years or more.