Continuity mistake: When Jesse and Becky first arrive at the Fuller house, in the closeup Becky's left hand is holding out the duffel bag (similar pattern color on her shirt) in front of her, as she and Jesse poke their heads through the doorway, but in the next wideshot it's her right hand holding out her black and white suitcase in front of her.
What We Owe to Each Other - S1-E6
Visible crew/equipment: You can see a crew member hand Janet a stack of papers behind her back.
Chapter Seven: The Massacre at Hawkins Lab - S4-E7
Continuity mistake: Eddie is still wearing a denim vest he took off his body and threw at Steve a few seconds earlier. When the camera cuts away and back, the vest is gone again. (00:15:19)
Character mistake: In the 11/14/2005 US Army Rangers report about Peter MacLeish, the word captain right under MacLeish's signature is misspelled "captian."
Soccer + Desi + Merchant + Titan - S4-E5
Other mistake: A spectator has a vuvuzela in his hand. This is a horn that emits a very loud monotone. It is common at soccer matches where he is. But what is he doing with it? He is looking through it as if it were a telescope. (00:32:05)
Episode #1.3 - S1-E3
Continuity mistake: In the cafe before Martin cries "Help me!" he holds two sandwiches in his left hand. A shot later one is suddenly in his right hand.
Continuity mistake: When Tulip hands over her driving licence after she's been pulled over, she puts a ring on her left hand and hands the licence over with that hand, then the angle changes and she's using her right.
Continuity mistake: When Pop shows Luke the photo of him, Luke takes it from him and holds it with his right hand, but in the next shot, he is suddenly holding the photo with both his right and his left hand.