"Shoot 'Em Up" was produced on a budget of $39 million. Principal photography took place in Toronto and lasted fifty-five days, with Hong Kong's Peter Pau serving as cinematographer. Before filming, Owen and Giamatti were trained in firearms. Although he found the stunts physically demanding, Owen resolved to perform most of them himself. In the skydiving scene, he was aided by a Cirque du Soleil safety harness. Eighty firearms were used during production, and $70,000 of the film's budget was allocated for 6,000 squibs.