Thankfully, poker winnings both online and in casino poker rooms are non taxable at this time. The government is attempting to pass laws that will require you to claim any and all winnings from online gambling, but at this time, as a casual poker player, there is no need to claim your poker winnings.
Typically, the government sees all gambling in the same light. As a losing proposition for the majority of people. There are regulations, however, for "professional" gamblers. If you make a living playing cards, you are considered by the Canadian government to having a profession, and your winnings are taxable. If you "apply skill and investment to achieve a profit", you should be paying taxes. As quoted from the Canadian Customs and Revenue Agency: "Winnings derived from a dedicated approach to gambling is taxable income".
If you do play poker for a living, there is good news. The majority of the investments made to play poker can now be tax write offs. Travel, meals, hotel stays, etc. that are involved in your poker playing can now be written off.
SPECIAL NOTICE: I received much of this information directly from the mouth of my tax guy. He told me that I needed to keep a record of all profits from online poker, so in the event I was audited, I had all of the information about the extra money going through my bank account. Any winnings (and losses) as a result of online poker, or real life poker, should be kept and recorded. I recommend using Click2Pay for online poker, because you can transfer funds between poker rooms, without the hassle of using Credit cards. Click2Pay also provides an ATM card, that can be used to withdraw money directly from your account, providing nearly instant access to your money. This takes away from having to get the poker room to send you a cheque, and having to deposit it into an account. It also helps to keep track of your poker bankroll.
Legal Notice: All information on this website regarding tax laws is for informational, and is not legal advice. You should always consult with legal council if you have a legal issue.