The Wildrose had originally planned to hold a leadership vote in June, but the party decided to move that up to be ready for what is being speculated will be a spring election.
Telephone balloting is to take place over 12 days beginning March 16 and the winner will be announced at an event in Calgary.
Interim leader Heather Forsyth is not running for re-election.
Three candidates have announced plans to run: current Wildrose MLA Drew Barnes, former Conservative MP Brian Jean and former Strathcona County mayor Linda Osinchuk.
The leadership vote became necessary when former leader Danielle Smith crossed the floor in December along with eight of her caucus colleagues to join the government.