Objectives: To detect the effect of complete oral rehabilitation on the general health of mentally retarded children and to predict the success and failure of different types of dental restorations done to these patients.Subjects and methods: Fifty two children with mental retardation received dental treatment under general anesthesia and followed up after 6 months for changes in body weighed, serum ferritin, albumin &Hb and evaluation of the types of the dental treatment and restorations was done. Paired T-test was done for statistical analysis for the hematological results and body weight was done.Results The results of weight changes and changes in serum hemoglobin and ferritin were significant and the number of extractions was more than restorations. Stainless steel crowns were used more frequent than amalgam & composite restorations. The success rates of stainless steel crowns were higher than amalgam and composite restorations.