Continuity mistake: There are red and white puffy paper decorations on each side of the door entering the gym for the dance-off. However, within a few seconds, the decorations on the left side completely disappear.
Continuity mistake: When the students are dancing to "Hound Dog" at the National Dance Off, they go up to the TV camera and start waving. You can see in the crowd a girl in a blue dress jumping up and down, but when we see it on the TV from the Frosty Palace, the girl is nowhere to be seen.
Audio problem: When Johnny Casino & the Gamblers perform "Hound Dog" at the National Dance Off, you can hear the song, but if you look carefully you can see it does not match the lead singer's lips.
Continuity mistake: When Cha-Cha receives the award from Principal McGee at the end of "Born to Hand Jive" at the National Dance Off, Putzie is giving Jan a piggy-back next to the Principal. However, in the next scene, Putzie is giving Jan a piggy-back right next to Cha-Cha. (01:14:00)
Continuity mistake: When the waitress is cleaning off the table after the kids leave, the plates on her tray all appear to be empty. But Danny's and Sandy's plates are completely full when they leave, and no one touches their food. Kenickie takes one bite of a burger on a different plate, but not nearly enough to empty it.
Continuity mistake: When Kenickie says to Rizzo in the soda parlour, "How about if I finish with you, huh?" there is a tomato ketchup squeezer on his side of the table. In the next scene when Rizzo says, "Finish this!" and throws the glass of liquid at Kenickie, the ketchup squeezer has moved to her side of the table, and in the next scene, when Kenickie is covered in liquid, the ketchup squeezer is back in its normal position. (00:52:00)
Continuity mistake: When Rizzo is lying on the bench, and kicks off Sandy and that other chick, Sandy is singing, however her mouth is not moving at all.
Continuity mistake: In the lunch scene, when Rizzo and Marty first sit down, there is a half-eaten apple in front of Rizzo's lunch tray that keeps disappearing and reappearing between shots.
Continuity mistake: Sonny has a lunch bag in his hands when they arrive at school. After they see and talk with Zucco, the bell rings and they head for class. As they start leaving, Sonny doesn't have his lunch bag anymore.
Suggested correction: While the T-Birds are still outside you see Sonny putting his lunch in his coat pocket.
Continuity mistake: At the end of the prep rally, after Sandy confronts Danny, she is leaning on a car crying. Frenchie comes up to Sandy to console her. Watch Sandy's head, in one shot her head is up then in the next it is down.
Visible crew/equipment: When Danny is about to play basketball with the other students and Coach Calhoun is speaking to him, you can see the shadow of the boom mic behind the coach.
Continuity mistake: At the end of Principal McGee's final speech before the students' graduation carnival, the Principal gives Blanche a tissue and says, "Oh Blanche, stop blubbering". Blanche then puts the tissue over her nose, but in the next scene when she bursts into tears, the tissue has opened up and is covering the left side of her cheek.
Continuity mistake: During the dance off, Sandy and Danny are dancing in the center and everyone is watching them. Behind Sandy, Cha Cha walks out and puts her hands on her hips. Then, the camera does a close up of her doing this. So she actually walked out twice.
Continuity mistake: During the song Summer Lovin', Rizzo lies down on her side on a picnic bench and puts on sunglasses. In the next shot, when she kicks Sandy and another girl off the bench, the sunglasses are off. In the following shot, they are on again. (00:16:13)
Continuity mistake: Rizzo is singing the Sandra-Dee song in Frenchie's bedroom. When she sits at the desk, you can just see that the chest of drawers are all closed fully behind her. However, later in the song Rizzo jumps off the bed. As she passes, then sits back at the desk, the second drawer down is now partially open. No one goes near it during this time, as all the girls in this song are on the bed.
Continuity mistake: During the sleepover, Rizzo gets off of the bed with a cigarette in one hand and the wine bottle in the other. In the next shot, the cigarette and the bottle have switched places.
Other mistake: The entire "Greased Lightning" number repeatedly goes in and out of focus.
Continuity mistake: After Vince Fontaine begins the National Dance Off with Johnny Casino & The Gamblers, Mr. Rudie is seen walking down some steps near the stage, but in the very next shot he is seen at the bottom of the steps, putting his hands up to Vince.
Continuity mistake: In the song "There Are Worse Things I Could Do," between the lines "Out of spite or jealousy" and "I don't steal and I don't lie", Rizzo's hand jumps from the side of her book to the top of her book, near her face.
Continuity mistake: During the dance, there's one song where the guys stand in one line and the girls in another, and the couples take turns walking down the middle. In one shot, Danny is placing Sandy in line, and a couple (the woman has a blue dress on) is already starting down the middle. Then it cuts to another angle and no one is in the middle. Back to the first angle, and people are in the middle again.
