Continuity mistake: When Karen is sorting out her clothes at her work desk, the black sweater hanging over the desk lamp disappears then reappears. (00:26:40)
Continuity mistake: When Grace finally decides to move into Will's apartment near the end, we see Will eating a tub of ice cream. Between shots the ice cream tub lid jumps from being on the table behind Will, to suddenly sitting right in front of him. (00:42:00)
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)
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 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.
Continuity mistake: When Will is cleaning the tray, and in all following shots, from when he leaves the room, to when Karen walks over to Grace, to tell her to go get Campbell, there is a wine bottle which keeps jumping from the edge of the blue sink counter, to the edge of the counter which has the cooking gas-hobs on it. (00:09:55)
Continuity mistake: When Will and Grace sit on the rocks in the meditation room, at the end of the episode, the position of Grace's coat changes between each shot. (01:22:00)
Will on Ice - S1-E11
Continuity mistake: When Will and Grace play the "love her, hate him" game, they open a magazine up. In the next shot you can tell it's on a different page, because the layouts have changed. (00:05:45)
Boo! Humbug - S1-E5
Continuity mistake: When Will grabs the silly string from the table, he pulls off the yellow lid and drops it to the floor. In the next shot the lid is on the coffee table. It alternates from on the table/floor for a few following shots as well. (00:59:25)
