Across Canada, impaired driving is driving with a blood alcohol concentration (BAC) above .08 or driving while impaired by alcohol or drugs. It is a serious offence to fail to give a breath sample when requested by police, with penalties the same as those for driving while impaired. A first offence conviction of impaired driving results in a criminal record, a minimum $1000 fine, and a driving prohibition for a minimum of one year.

Routine screening upon entry into Canada includes the question, “Have you ever been convicted of a crime?”  If you have been convicted of impaired driving - even if no collision was involved - you may be denied entrance.  Even with no other criminal violations. Think carefully.  Don't lie about any convictions, regardless of how 'trivial'.  This is especially true if  you're entering from the U.S.  Increased cooperation between Canada and U.S., as part of post-911 security measures, means that the border agent could already have access to criminal records. Lying/forgetting about a conviction could get you barred from entry into Canada for many years.