The Criminal Code, R.S.C. 1985, c. C-46 [Criminal Code] imposes a general prohibition on interception (recording) of private communications, but then provides an exception where one of the parties to the private communication consents to the interception of that communication. Thus, broadly speaking, Canadians can legally record their own conversations with other people, but not other peoples' conversations that they are not involved in.

http://www.legaltree.ca/node/908