The opening action scene took six months of training and four days to shoot.
Carrie-Anne Moss performed the shots featuring Trinity at the beginning of the film, and all the wire stunts throughout, herself.
Carrie-Anne Moss twisted her ankle while shooting one of her scenes, but decided not to tell anyone until after filming, so they wouldn't re-cast her.
The studio insisted on a great deal of explanatory dialogue, as they described the screenplay as "the script that nobody understands."
Prior to pre-production, Keanu Reeves suffered a two-level fusion of his cervical spine, which had begun to cause paralysis in his legs, requiring him to undergo neck surgery. He was still recovering during pre-production, but insisted on training. Stunt coordinator Yuen Woo-Ping let him practice only punches and lighter moves. Reeves trained hard, and even requested training on days off, however, the surgery left him unable to kick for two out of the four months of training. As a result, Reeves did not kick much in the film.