Nearly a million children in the UK are living with violence in their homes, according to a new report.
This can lead to kids having problems at school and doing badly in exams.
International children's charity UNICEF's study also found there were 275 million kids across the world living with domestic violence.
The charity wants to highlight the number of kids affected to show how much help is needed and raise funds to protect children at risk.
The report found that kids who live with domestic violence may have a low image of themselves, feel aggressive and have problems controlling their behaviour.
Report spokesman Dr Amaya Gillespie said more work still needs to be done: "We are just beginning to develop a clearer global picture of the problem and are in a position to call for action by governments and communities to stop the exposure of children to domestic violence."
If you need help or advice, visit Childline's website or The Hideout by using the right hand link or call Childline on free telephone 0800 1111