Matt LeBlanc had dislocated his shoulder on set attempting a sight gag. As a result, his arm was in a protective sling. At the beginning of this episode, Chandler overhears Joey bouncing on his bed and falling off. This was written into the story to explain why the character would be wearing a sling.
After Matt LeBlanc injured his shoulder taping the previous episode (The One Where No One's Ready (1996)), he was rushed backstage to receive medical attention and was surprised to see Anthony Edwards of ER (1994) - which was filmed at a nearby soundstage - dressed in character as Dr. Mark Greene. Though LeBlanc knew Edwards wasn't a real doctor, he was concerned about whether or not he also suffered a head injury as well.
Series producer Marta Kauffman has stated she regrets the stalker storyline and that "We did a lot of rewriting on that to make that work."
David Arquette, who plays Malcolm, the man following Phoebe, starred in the Scream franchise with, and later married, Courteney Cox, who plays Monica. Cox and Arquette later divorced after nearly 14 years of marriage.
When Rachel and Joey are sitting at Monica's table and Joey is eating jam, he has it all over his face. Rachel tries to tell him, and Jennifer Aniston can be seen cracking up from behind, as she's trying to conceal her laughter.