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.
Revealing mistake: Alex tries to commit suicide in the swimming pool. Spencer and Baz rescue him by lifting him to the water's surface and floating the unconscious Alex across the water's surface. Just before he reaches the side of the pool the unconscious Alex reaches out and touches the side wall of the pool.
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
Audio problem: When Mr Baxter punches Mr Hicks in the sports hall, a punch sound can be heard before Mr Baxter's hand makes contact with Mr Hicks' face.
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.
Visible crew/equipment: When Mr. Hussain gets out of his car to collect his family to go to court, the boom mike is reflected in the car window.
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.
Revealing mistake: Carlene makes Joanna a cup of coffee in the common room after finding her drunk in the toilet. Joanna refuses to drink it and drops the cup, breaking it - it's obvious that there was never any coffee in the cup.
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.
Audio problem: When Matthew runs out of the hall after taking part in the play and being frightened by the gun, you can hear Mrs. Munroe shout "quiet!" but you can see that her mouth doesn't move.
