A special cabinet meeting has agreed to set up a new Irish Refugee Protection Programme, including special reception centres to process arrivals.
The figure of 4,000 will include family resettlements, and also includes the figure of 1,100 previously agreed by the government.
The scheme will cost around 12 million euro per year, for every thousand refugees housed in Ireland.
Justice minister Frances Fitzgerald says it's the first step in trying to deal with the humanitarian crisis facing Europe.
