Visible crew/equipment: There is a boom mike shadows on the walls of Andrew's living room.
Visible crew/equipment: There is a boom mike shadow on the wall behind Cathy after Mr. Keating tells her to go outside .
Visible crew/equipment: There is a boom mike shadow on Pamela's head when she, Trisha and Suzi are talking to Miss Peterson and Mrs. McClusky.
Episode #4.6 - S4-E6
Visible crew/equipment: A boom mike shadow can be seen on Pogo's head during registration.
Episode #4.3 - S4-E3
Visible crew/equipment: A boom mike shadow can be seen in the kitchen when Clare is talking to her mum.
Visible crew/equipment: A boom mike shadow is on the blackboard when Mr. Hopwood is taking the register and again later on when Hopwood is asking Justin if he knows where Andrew is.
Visible crew/equipment: There is a boom mike shadow on the green machine next to Pogo when Mr. Hopwood sees him using the saw upside down.
Episode #4.6 - S4-E6
Visible crew/equipment: There is a boom mike reflected in the door window when Alan stops Tucker from going after Booga.
Episode #4.5 - S4-E5
Visible crew/equipment: A boom mike shadow can be seen in the library when Suzi sits with Tucker.
Episode #4.3 - S4-E3
Visible crew/equipment: There is a boom mike shadow visible during Miss Peterson's registration.
Continuity mistake: Mrs McClusky's first name is Brigit, but the sign on her office door says Mrs. M McCluskey.
Visible crew/equipment: There is a boom mike shadow on the wall behind Tommy when Alan says he has stopped smoking and started eating sweets instead.
Visible crew/equipment: A boom mike shadow can be seen on the wall behind Cathy when Miss Peterson wants a word with her.
Visible crew/equipment: There is a boom mike shadow on the wall behind Mrs. McClusky at the PTA meeting.
Episode #4.5 - S4-E5
Visible crew/equipment: A boom mike shadow can be seen in the library when Mr. Thomson tells Tucker to leave.
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.
Episode #4.9 - S4-E9
Continuity mistake: In the final scene when Miss Peterson is having a private word with Cathy about her attitude, the classroom door closes by itself.
Episode #4.6 - S4-E6
Continuity mistake: Just before Gerry, Ruth and Cathy go into the toilets Cathy is standing on the left - the angle changes and Cathy is now standing between Ruth and Gerry. Later on when they ask to go outside to get away from the puddles the three girls are standing close together, the angle changes and they are standing further apart.
