Bitcoin is Fast

Posted by Bitcoin Basics

You can send a bitcoin transaction from one address to another in less than 5 seconds by announcing the transaction to the Peer to Peer Network.

Bitcoin Transactions are completely validated after 3 block confirmations which takes on average 30 minutes

For small transactions its safe to wait for the first announcement, for larger transactions with unknown or untrusted parties you may want to wait 3 to 6 block chain confirmations.