Continuity mistake: After Karen takes her black top off and throws it down on the table, whilst talking to Jack as they first meet, in following shots the top changes position a few times. (00:37:40)
Visible crew/equipment: When Karen offers her hand to Jack when they first meet, you can see the boom mike at the top of the shot. (00:37:25)
The Unsinkable Mommy Adler - S1-E13
Continuity mistake: When Grace is reading through her diaries, through all following shots in the scene the position / location of the yellow, furry diary on the floor keeps changing. (00:37:40)
Continuity mistake: In the poker scene at the beginning of the pilot we witness Will, Jack, Rob, and others playing cards. Shortly after Jack asks for "four cards please" watch the bottom left of the screen as a hand (presumably Will's) deals Jack a single card. In the next shot Will appears to have not dealt Jack any cards yet and when he does he gives Jack five cards, add that to the single card he gave in the previous shot and the Ace Jack kept from his original hand and we get a total of seven cards. Two more than Jack should have had if the hand was dealt correctly.
Continuity mistake: When Grace enters Will's office, while he is spinning around on his new office chair, she goes and puts her black purse down on the desk. In the next shot it is positioned differently. (00:04:30)
Continuity mistake: After Will and Grace make Larry drop the birthday cake, there is a black woman standing behind then, an a green shirt. As Will and Grace then start to shout at each other, the woman walks away three times between shots.
Continuity mistake: After Kevin throws the contract paper down onto Will's desk, the items on Will's desk, and the contract itself, change position a few times in the following shots. (00:27:05)
Continuity mistake: When Will and Grace are talking to the nun about buying the car off of her, the amount of Burberry scarf showing out of Will's coat is inconsistent with each shot change.
Continuity mistake: After Jack and Karen have locked Will and Grace in the bouncy castle, Grace throws her black purse down into the corner, then her and Will start talking. During their conversation the position of the purse keeps changing.
The Truth About Will & Dogs - S1-E10
Visible crew/equipment: When Grace is trying to persuade Will to come out to the cinema with her, the boom mic is visible at the top of the shot. (00:34:35)
Home Court Disadvantage - S6-E3
Continuity mistake: When Leo walks into the club to show Karen his highschool yearbook, Grace is eating a bowl of bagel chips. In one shot the bowl is full, then suddenly empty, then full again. (00:17:30)
Brothers, A Love Story - S3-E14
Continuity mistake: When Karen reads Stan's will and sees that a third of his money will go to charity, she goes woozy in her chair. In this shot the table is free from loose jewels, yet in the next shot two rings are sitting on the table. (00:10:45)
Continuity mistake: When Grace gets out all the videos which hint Will's 'secret', she puts the bag on the table, but in the next shot it's in her hand. Between these same shots a sticker also appears on one of the video cases. (00:29:50)
Boo! Humbug - S1-E5
Continuity mistake: At the end of the episode, "Buzzy Wuzzy" takes her bee mask with her and they leave. But when Will and Grace dive for the jawbreaker, the bee mask is back on the coffee table. (01:01:25)
Continuity mistake: When eating in Will's office, Grace eats salad from a plastic container. Through the scene the salad in the container changes colour, position etc. Also between shots, lettuce appears on Grace's fork. (00:28:05)
Continuity mistake: Following the argument between Will and Grace when she returns from City Hall, Karen tells Grace she "thinks it's time for a couple of blue bibbies." Watch closely as she removes the lid from the pill bottle, takes out some pills, and puts the lid back on. The scene shoots to Grace and we hear Karen shaking the closed bottle. When the scene shoots back to Karen we see that the pill bottle is open again and Karen closes it yet again.