Continuity mistake: When Dexter leaves on his boat there are fishing poles behind his seat, but when he turns back around and you see him going away on the boat they have gone.
Let's Give the Boy a Hand - S1-E4
Continuity mistake: A photograph of a landfill is shown from when Dexter is a child, but when Dexter goes to visit the location of the former landfill, an old church can be seen in the background. This church likely predates the landfill as evidenced by its Gothic-style architecture. (00:32:00)
Our Father - S3-E1
Continuity mistake: When Dexter and Vince are next to the dead girl, in the side shot, the tied string from her top is visible on her back and her hair is to the side. But in the overhead shot of her, her hair is covering the tied string and spread more over her back.
Continuity mistake: Deborah walks out with the yellow shirted man in front of her. Next shot after Quin leaves, the same man re-exits the room. (00:14:00)
Just Let Go - S6-E6
Continuity mistake: When Travis meets his sister at the school she works at, a chalk board with nothing on it can be seen behind Travis. A couple of shots later and there is a piece of paper attached to the chalk board. (00:30:35)
Continuity mistake: When Dexter and Masuka are discussing wanting to go home Dexter throws a can toward the bin and misses, landing by Masuka's chair. In the next shot as Masuka leans down to pick it up it is closer to the bin. (00:39:30)
Everything Is Illuminated - S5-E6
Continuity mistake: Lumen has a dark "H" shaped scratch on her right shoulder. A few minutes later, its turned 90°, like a sideways "H," and it is very faint. (00:22:05 - 00:32:35)
Continuity mistake: Episode 3 begins with Dexter at the beach during a funeral. He is wearing a pair of stylish sunglasses. At the start of episode 4, Sgt Doakes is investigating a crime scene at the beach. He is wearing the same pair of sunglasses. Given the tense relationship between the two characters, it is unlikely they would share accessories.
Continuity mistake: Deb moves in with Dexter to his apartment in a 2nd bedroom during season 2 following the ice killer's kidnapping and attempt on her life. But in Season 5 when they try to share this apartment again, it's only 1 bedroom now?
Continuity mistake: When Dexter is packing kill tools for the road he "packs light" and chooses a knife and hammer. However once he's at the hotel room setting up the kill room he unrolls his entire set of tools like he does at all the other murder room scenes.
Continuity mistake: In the shot where Angel gives Dexter a gift from the recently deceased Maria's office, we see Masuka through the window in front of Dexter. Masuka then enters Dexter's office, showing Masuka in two places at once for at least two seconds. (00:30:55)
Suggested correction: That's not Masuka we see in the window. Not only is the person seen through the window wearing a different shirt, he's not bald like Masuka.
Seeing Red - S1-E10
Continuity mistake: When Angel is at the bar, the girl he is talking to has a drink held up by her face when viewed from behind. In every shot from in front, the drink is on the table.