The Penticton MLA said in a statement published by a local newspaper that he was stepping down to spend more time with his grandchildren.
"There also comes a time when it must come to an end and the torch must be passed on to the next generation of leaders who share the same passion to make a difference in the communities we serve," said Barisoff.
He cited the establishment of the Penticton Okanagan College campus, which is now the Jim Pattison Centre for Excellence, and the Skaha Bluffs Provincial Parks as two of the notable achievements in his final term in office.
But the popular MLA was sharply criticized last month by the province's auditor general for failing to properly monitor the expenses accounts of MLAs, as part of his duties as the speaker of the house.
Barisoff was first elected in 1996 — squeaking past the NDP incumbent by just a handful of votes — and has served as Speaker of the House since 2005.
According to the Canadian Taxpayers Federation he will collect a pension of nearly $91,000 a year, second only to Gordon Campbell among the B.C. Liberals.
'Death by a thousand cuts'
Barisoff's announcement is the latest in a string of Liberals who won't be running for re-election next May, including Harry Bloy, Kash Heed and Kevin Krueger.
University of Victoria political scientist Michael Prince says even though many of the retirements are expected, they add up to a political distraction for Premier Christy Clark.
"It's almost a death by a thousand cuts here, or drip by drip through the summer," Prince said.
"No doubt into the fall we will have another Liberal MLA, and perhaps the odd occasional announcement from an NDP MLA, saying, 'I've had enough.''
Prince says the growing number isn't good for Clark's image.
"It just creates an air of uncertainty around the Christy Clark cabinet and government, which is precisely what she does not need," he said.
"She needs to project an image of business as usual, 'We're governing, I've got a strong team around me, we've got a great set of candidates heading into the next election.'"
Prince says the real test for Clark will come when high-profile cabinet ministers like George Abbott, Kevin Falcon and Rich Coleman announce their intentions later in the fall.