The royal commission into child sex abuse will conduct its first public hearings in Perth into an unnamed organisation from April 28.
The hearing is set down for two weeks and the organisation involved will be named about a month before hearings begin.
Among the possible WA child sex abuse scandals the commission could investigate is systematic abuse that occurred in State-run boarding hostels.
A 2012 inquiry headed by former judge Peter Blaxell found public servants and parents ignored at least 20 attempts to warn them about abuse over two decades.
A case in the 1990s featured the Christian Brothers that resulted in a $5 million out-of-court settlement for 250 men.