In fact, Potter fans have snapped up so many copies of the second movie that it's outsold the previous record-holder.
And that was Harry Potter and the Philosopher's Stone!
It sold more than 1,012,000 copies in the first two days.
Some shops even opened up at midnight to cope with the thousands of fans who wanted to buy it straight away.
The film was an instant smash hit when it was released at the cinema in November 2002.
The DVD contains loads of extra bits, like deleted scenes, interviews with JK Rowling and director Chris Columbus, and a car game called the Forbidden Forest.