The average deposit for a mortgage in Dublin has increased to €51,000.
The data, which was compiled by the banks, shows that the amount has risen 38% in just one year.
Outside the capital the average is now €20,000, up from €16,000 in 2014.
The other large cities in Ireland are also seeing high levels of mortgage deposits.
In Cork city the average is around €32,000 to secure a mortgage, up €8,000 from 2014, while the average deposit in Galway city is now €27,000.