When Bill's mother plays during the first flashback, her hands are clearly mis-synched with the music. Her right hand is in the air when the melody plays, and her left hand doesn't move.
When Bill looks at George's photo album, the piece of paper with the word "George" on it has a bend in the right corner when Bill looks at it. But when he sets it down in the next shot, the paper is entirely unbent.
When Ben greets the class, Richie is wearing a shirt with vertical stripes. But when Henry is sent to the principal's office, he walks by Richie who is now wearing a shirt with solid colors.
When Tom takes the bottle of champagne out of the refrigerator, he is holding it in his right hand. In the next shot the bottle instantly jumps to his left hand.
When Beverly walks out on Tom, she is only carrying a suitcase and a coat. However, when she comes out of the apartment, she has an additional bag over her shoulder that she didn't have when she left the apartment.
When the Loser's go to Eddie's house, he says that he wishes the summer would never end. However, in the next few scenes, the Losers are seen at school.
Mike: I'm just a concerned citizen, Chief, and I'd call six children missing or dead a cause for alarm here.
Rademacher: Maybe just a rash of runaways. Kids get itchy feet.
Mike: Right. A five-year-old with a toy car gets itchy feet? What, a seven-year-old treks down to Acapulco for a wild weekend?
Pennywise: Oh, you want it, don't you, Georgie? Oh, of course you do. And there's cotton candy and rides and all sorts of surprises down here. And balloons, too. All colors.
Georgie: Do they float?
Pennywise: Oh, yes. They float, Georgie. They all float. And when you're down here with me, you'll float too!
Cyndi: Are you okay?
Ben: I don't think I am, sweetheart. Not tonight, not at all.
Cyndi: Are you going to kill yourself?
Ben: No, I don't think so. Although it might be better if I did.
Cab Driver: What's in Maine? Family?
Beverly: Friends. The best I ever had.
Richie: Hi, Bill. How you doing, Eddie Spaghetti?
Eddie: Don't do that. I hate it when you do that. And don't call me Eddie Spaghetti.
Richie: Oh, you love it, Eddie. It's what makes you so chuckalicious.
Richie: This is Stan the Man Uris. Stan, he's a Jew, which means he's really smart and says "Oy" a lot.
Richie: If I were you guys, I wouldn't pay to see a monster movie! I'd just stay home and look in a mirror!
Mike: This is the Derry Standpipe. It supplied all the water to the town, until a big disaster back in 1900. Maybe the biggest mystery is how 253 settlers disappeared without a trace.
Mrs. Douglas: Thank you, Michael, for that illuminating if somewhat morbid history.
Pennywise: I'll kill you all! Ha! I'll drive you crazy and I'll kill you all! I'm every nightmare you've ever had, I am your worse dream come true! I'm everything you ever were afraid of!
Bill: You killed my brother George, you bastard! Let's see you now. Let's see you now. It's scared of us, you know. I can feel that, I swear to God I can. I want to kill it. Help me. Please help me. Help me.
Pennywise: That's it, let go! Be afraid! You all taste so much better when you're afraid.
Bill: Hurry, Bev! Kill it!
Pennywise: Kill? Ha! Me! You are priceless, brat. I am eternal, child. I am the eater of worlds... and of children. And you are next.
Filming location: New Westminster, British Columbia
Music: It's All Right (Curtis Mayfield)