Mentally disabled children have higher safety threats so safety measures guidelines education for their parents is very important in order to reduce them. The purpose of this study was to evaluate effect of parents' knowledge and practice regarding safety measures on safety threats of their children with mental impairment. Study design: A quasi experimental design (pre and posttest) was used to fulfill the aim of the study. Setting: The study was conducted in Eltarbia Elfekria School for children with special needs, at Shebein El.kom City-Menoufia Governorate. Sample: A purposive sample of 200 parents' of children with special needs was selected to carry out this study. Three instruments were used in this study including: Parents' Knowledge about Safety Measures, Parents' Practice about Safety Measures Guidelines and Children Safety Threats Scale. The results of this study showed significant improvement in the mean total scores of parents' knowledge about safety measures on posttest than pretest. Also, mean total parents' practice scores regarding safety measures guidelines were significantly different immediately post intervention than pre intervention. Moreover, mean total score of parents' practice regarding their children safety threats were significantly improved post intervention. The study concluded that implementation of educational program about children safety measures improved parents' knowledge and practice on posttest than pretest. So, this study recommended that educational program about children safety threats should be implemented to parents at all special education schools to help them adapt and cope better with their children impairment.