On October 25, 2007, Tlustý played his first regular season NHL game against the Pittsburgh Penguins, scoring two goals in his début. His first goal was originally a shot by Alex Steen, but it deflected off of Tlustý's backside and went in the net. Thirty-five seconds later, he scored with a wrist shot from the wing. He earned his first assist on November 2. When he got into the NHL he wore number 41. However, he later switched his number to 11.
On January 15, 2009, Tlustý registered a career high of 3 points, all assists, in a game against the Carolina Hurricanes .
Tlusty will finally take a regular spot on the Leafs this season.