Background: Oral disease such as dental caries has a negative impact on child quality of life, child growth and amount of streptococcus mutans count. Dental treatment under general anesthesia is a way to provide a relatively safe treatment allowing complete elimination of the caries and rehabilitation of the teeth which lead to subsequent improvement in the quality of life, increasing child BMI and decreasing amount of streptococcus mutans count in saliva. Aim: to evaluate quality of life using DDQ (dental discomfort questionnaire), Body Mass Index (BMI) and Streptococcus mutans count before and after full mouth rehabilitation under G.A. Material and methods: 103 children with their age from 2 to 7 years old were included. Those children referred to the general anesthesia (G.A) unit for treatment. The parents were asked to fill out the DDQ on their behalf. Each child was then weighted using calibrated digital scales and their height measured in a standardized fashion using a rigid scale and Body Mass Index (BMI) of the children was calculated [weight (kg)/height (m2)]. Stimulated saliva was collected from each child by using a plastic syringe (SAF 5ml) or cotton swab and then delivered to the microbiology department in Cairo University for analysis which whole saliva was diluted with 0.9% NaCl in series up to 105and 3 drops of 20 μL of each dilution were dispensed on mitis salivarius agar base plus 0.2 units/mL of bacitracin (MSB) to determine streptococcus mutans (S.M) and then Plates were incubated for 48 h at 37 °C. Colony-forming units (CFU) were counted and the results expressed as CFU/mL of stimulated saliva. One month postoperatively DDQ was determined from each child .the weights and heights of each child were recorded by the same examiner using the same equipment and saliva samples were taken and analyzed for the previously mentioned elements by the same laboratory to avoid any analytical variation. Result: the result of the study showed that there was a significant decrease in DDQ scores, significant increase in BMI and significant decrease in streptococcus mutans count after treatment under general anesthesia. Conclusion: this study concluded that Full mouth rehabilitation under general anesthesia improves quality of life in children, improves child growth and increase child BMI and Streptococcus mutans count decreased after treatment under general anesthesia.