3.02 - From The Edge Of The Deep Green Sea
*When Nathan and Lucas are playing a pick-up game at the Rivercourt, Lucas' shirt is drenched in sweat. The next time you see Lucas his shirt isn't wet at all. But then it's soaked in the next scene.

3.03 - First Day On A Brand New Plant
*At the point when Lucas and Haley realize their are right next to each other and right next to Nathan's as well, Lucas has short hair that is not really styled in any particular fashion, no facial hair, and a dark blue shirt on. In the next scene, where he is walking with Brooke to her locker, his hair is about a quarter to half inch longer and styled, he has noticeable facial hair, and a shirt that is a tad bit lighter.

3.06 - Locked Hearts And Hand Grenades
*When Haley is talking to Chris after putting "Janis Joplin" on the map, her hair is up, but it changes to down alternately: when the camera is on her face, her hair is up; when you can see the back of her head, her hair is down.
*Earlier in the season it is revealed that the locker assignments are alphabetical by last name. In this episode, Rachel walks up to Peyton while she's at her locker and offers her a bootleg CD. Soon after their conversation ends, Rachel opens a locker that is just two or three away from Peyton's. Rachel's last name is Gatina and Peyton's is Sawyer.

3.08 - The Worst Day Since Yesterday
*DISCLAIMER:This Is Regarded As A Mistake, But Is Not One!
In one episode, Brooke calls Peyton by her full name "Peyton Elizabeth Sawyer" (her mother even says that her middle name is Elizabeth). However, when Peyton goes to get Haley, when Haley is with Chris, Peyton tells Haley how, lately she's been angry, and Peyton says that Brooke calls her "Peyton Marie Sawyer - PMS". PMS is just a joke, it is established that Peyton's middle name is Elizabeth, after her birth Mother Ellie- Elizabeth

3.09 - How A Resurrection Really Feels
*When Haley goes to leave Nathan's room, the door is closed. The scene cuts to Nathan and when it cuts back to Haley the door is open.

3.11 - Return Of The Future
*Lucas's iPod disappears when he meets up with Keith in front of their house to play with the football.

3.13 - The Wind That Blew My Heart Away
*While Nathan and Haley are in the mansion, as the lightning flashes, Haley's scarf is hanging at the sides of her neck. When the lights go off, her scarf is wrapped around her neck. When the lightning flashes again, her scarf is back hanging at the sides of her neck again.

3.22 - The Show Must Go On
*When the limo goes off the bridge, it lands upside down in the river. It's also upside down in the next season's premiere when it's hoisted out of the water by a crane. But it appears to be right-side-up in other shots when the inside is shown underwater. As the car is sinking, its unconscious passengers are shown sitting right-side-up. When Nathan swims in and gets trapped he is also right-side-up; the closed moon-roof is clearly visible above his head as he's yelling for help.