Background: Domestic injuries are one of the greatest public health challenges in the 21st century especially in low and middle income countries (LMICs) with considerable association between social and economic costs. These injuries are common among children under-five in rural Egypt. Poisoning, burns, falls, wounds are common causes of children injuries at their homes. There are so many factors that had a direct or indirect effect on children injuries including child age, gender and behavior, maternal education, family socio-economic status and number and home environment. Therefore, it`s important to increase mothers` knowledge and practice continuously to be cared of their children. This study aimed to assess mothers' knowledge and subjective practice toward most common domestic injuries among under-five children. A cross sectional study design was utilized to accomplish this study at Mansoura locality from both urban and rural areas (Mansoura city and El-Baramoun village) through home visits. Convenience sampling technique was used in this study and 100 mothers of under-five children from both genders were included in the sample, while excluding children with special needs. The study was conducted throughout preparation phase, operational phase including literature review and developing the study tools and implementation phase including initial data collection. Results. Study results revealed that more than of the studied mothers had secondary education. Less than half of the studied children' age ranged from 2 to less than 3 years during occurrence of domestic injury, moreover about one fourth of them their injuries were caused by falls, in addition to about three fourths occurred due to unsafe home environment. Consequently less than two thirds of studied children exposed to low risk which can be treated at home. All of the studied mothers had improper practice regarding to burns, falls, poisoning. Conclusion. The home environment is a common place for injuries among under-five children in rural and urban areas in Mansoura locality. Additionally, mothers' subjective practices regarding to most common domestic injuries are improper and as well knowledge of them on such injuries are poor. Finally, it is recommended that continuous health education program and training courses regarding domestic safety for children and first aid measures for the mothers who have under-five children.