Robin Williams, who was a big fan of the franchise, provided Judith Hoag with information regarding her character through his comic book collection; the two were co-starring in Cadillac Man (1990) when the Turtles film went into production.
This was the highest-grossing independent film until The Blair Witch Project (1999), having made $135 million in domestic box office and $66 million in the foreign box office.
One of the early ideas floated around that the film would follow a similar approach to Who Framed Roger Rabbit (1988) in which the actors would be interacting with animated versions of the turtles. However, this idea was quickly scrapped in favor of pursuing performances in turtle costumes from Jim Henson's Creature Shop. Luckily, Jim Henson and his team were up to the challenge.
The actors who physically portrayed the Turtles also had cameo roles in the film: Josh Pais, who plays Raphael, plays a passenger in the back of a taxicab right after Raphael hops on the cab's hood. Michelan Sisti, who plays Michaelangelo, plays the pizza delivery man who delivers the pizza to the Turtles' sewer. Leif Tilden, who plays Donatello, plays the Foot messenger that meets April in the subway station. David Forman, who plays Leonardo, plays a gang member in the warehouse during Casey's fight with Tatsu. He's the one on Tatsu's right who takes a drag of a cigarette.
To help disguise how cumbersome and slow the turtles' costumes were, dialogue scenes were shot at 23 frames per second so that when they were played at the normal speed of 24 frames per second they appeared a bit sharper. For the same reason, fight scenes were shot at 22 or 23 frames per second.