Continuity mistake: Tarquin and Forbes arrive at school in Tarquin's sports car. The car keeps disappearing and reappearing during later shots of the car park.
Continuity mistake: In the panic when the hall is evacuated for the bomb alert, Sammy's tiara is knocked off, the angle changes and it is back on her head. Then when the pupils are allowed back in, Sammy and Alex are the first pupils back in the hall - Alex picks the tiara up off the floor and places it on Sammy's head.
Continuity mistake: When Matt is in his hospital bed talking to Cracker, the position of Matt's head changes between shots.
Continuity mistake: When Tanya, Emma and Annie dress as suffragettes and handcuff themselves to the goalpost the crossbar is level with their shoulders, but at the end when the lights go out and all three girls shout for help the crossbar is above their heads, and their arms have changed position accordingly.
Continuity mistake: Tanya and Karen Young are step sisters. In this series Tanya says her family came about by her father marrying Karen's mother, but in later series it had changed round, with Karen's dad marrying Tanya's mum.
Continuity mistake: When Liam and Justine are on the park bench Liam gives Justine the ring, as Justine puts the ring on her tie changes position from being over her arm to its normal position on the front of her shirt.
Episode #4.4 - S4-E4
Continuity mistake: When we see the pupils jumping the pommel horse during the PE lesson, Gripper does his jump and you can see there is a pupil with a dark blue shirt at the back of the queue, but when we see a close-up of the queue in the next shot, there is now a pupil with a light blue shirt at the back. Then when Richard Marks does his jump over the horse the pupil in the light blue shirt has disappeared.
Episode #4.4 - S4-E4
Continuity mistake: When the shopkeeper bans the two Grange Hill pupils from going into the newsagent, Pogo, Stewpot and Duane can be seen walking towards the shop, but in the next shot they are back in their original positions.
Continuity mistake: When Judi is lying on the ground after her fall, her school tie has straightened by itself.
Continuity mistake: At the start of this episode it is raining heavily, but when Cathy drops Alec off there is bright sunshine and the ground is dry even though Alec is still wet. But when the school is out in the playground after the fire alarm has sounded, the ground is wet again.
Continuity mistake: Mr Robson parks his red Vauxhall Cavalier outside the school gates with a blue VW Golf next to it backed up to the fence. When Amy walks in there is a different red Cavalier parked where Robson's car was parked, and the blue Golf has turned round and is now facing the fence.
Continuity mistake: In the cafe when Gerald says his line "must dash got a deadline to meet on the school magazine" the same girl (with long brown hair) walks behind him twice within a few seconds.
Continuity mistake: When the helicopter descends there is a passenger in the front seat, but as it lands only the pilot is on board. And when Mr. Parrott approaches two men jump out of the back seat of the helicopter to "kidnap" him.
Continuity mistake: Richard and Matthew are on reception duty, and Richard is hacking into Mr. Hargreaves' computer to see if he can find out what Hargreaves did with the money that was for the trip to Russia. The scene cuts to Mr. Robson's geography class where Justine has a message from Mrs. McCluskey to Fran. Richard and Matthew are seen in this class, but when we cut back to reception Richard and Matthew are still on reception duty.
Continuity mistake: After Fran has read the diary page about herself she rushes off to the common room and is right behind Richard, Ray and Nick, but when she enters the common room, Richard, Ray and Nick are already inside sitting down.
Continuity mistake: When Natalie and Raju are talking in the playground just before they rush off to the room where Justine and Chrissie are printing the T shirts, Natalie's hair changes position between shots from being over her back to over the front of her shoulders.
Episode #3.6 - S3-E6
Continuity mistake: Karen and Tracey are climbing the tree Adrian is behind Tracey, Karen tells Adrian not to come up as there's no room, but when the angle changes to looking down the tree trunk Adrian has disappeared, and less than a minute later Karen and Tracey are back on the ground.
Continuity mistake: In episode 16 Calley takes her boyfriend's works pass out of his wallet - the name on the pass is John Cooke. In this episode when the security staff look at the computer screen to find out whose pass let Calley, Ronnie and Georgina into the animal house, John's surname has changed to Hunter.
Continuity mistake: When Ayeesha and Akik walk into school Mr. Hankin's blue Morris Minor is parked next to a white Ford Escort mark 3 which the Timpson brothers are leaning on. The camera then goes back to Hankin getting out of his car - there is now a white Ford Escort mark 2 next to Hankin's Minor.
Episode #2.8 - S2-E8
Continuity mistake: Mr Mitchell and Carol are in the back seat of the police car looking for Trisha, and when they see her walking home alone they stop to pick her up. In the following scenes of the police car speeding through the streets you can see that Trisha is not in the car, only Carol and Mitchell are in the back seat, but when the police car stops to arrest the man who is following Cathy, Trisha is there again.