The leader of the Scottish Conservatives will be announced on Friday.
Russell Findlay, Murdo Fraser and Meghan Gallacher are on the ballot paper, with one of the three set to take over from Douglas Ross in Holyrood.
The field narrowed from six to three after Brian Whittle, Jamie Greene and Liam Kerr dropped their bid for the top job.
Polls closed for Scottish Tory members – of which there are believed to be around 7,000 – at noon on Thursday, with the result due to be announced at around 10am on Friday.
Whoever takes on the top job will inherit a difficult legacy from Mr Ross, who was driven out of the role following his decision to stand in the Aberdeenshire North and Moray East seat at Westminster in place of former MP David Duguid, who was recovering from a spinal stroke.
Douglas Ross announced he would step down as Scottish Tory leader during the general election campaign (Andrew Milligan/PA)
The decision irked MSPs and party members after Mr Ross had previously said he would stand down from Westminster to focus on Holyrood. He was forced to announce in the midst of the general election campaign that he would quit as leader after polling day.
The newest incumbent will also face a punishing first few days.
As well as an intense media round following the announcement on Friday, a ceremony to mark the 25th anniversary of devolution is being held at the Scottish Parliament on Saturday, with the new leader due to join others in making a speech before the King and Queen.
Within 24 hours, they will need to head to the Conservative Party conference in Birmingham, where they will undertake a number of engagements.
Appointments of their frontbench team are expected to take place next week.