Troops at CFB Petawawa are about to deploy to southern Afghanistan.
About 300 soldiers and their families are preparing for the departure.
Those soldiers - who are being deployed to work as administrative workers - will be joined by the base's main body of soldiers who are scheduled to depart for the mission at the end of the summer.
Ontario's Lieutenant-Governor David Onley and Ontario Provincial Police Commissioner Julian Fantino will be on hand for today's official departure ceremony.
On Thursday, the country's top military commander gave the House of Commons foreign affairs committee a cautious assessment of the insurgency on the ground in Afghanistan.
"The direct threat is still very real,'' said Gen. Rick Hillier, the chief of defence staff.
"The mission continues in a positive direction, but that threat remains high especially in the south of Afghanistan and especially, from our perspective in the west and north of Kandahar city itself.''
Since 2002, 82 Canadian soldiers have lost their lives during the Afghan mission.
With files from The Canadian Press
