Visible crew/equipment: When Dewey yells for Lois because the bow was put on the present, if you look to the left of Lois, you will see a crewmember kneeling down, handing Lois the red dress, who is holding a bucket of water. He quickly gets out of the camera's view. [This is on the DVD of the first season. Someone said on the audio commentary that after catching it, they deliberately left it in to see if anyone would spot it. It's still a mistake, but that's why it's there.]

Continuity: When Lois is yelling at the boys for playing with fire, the location of the green scissors on the table keeps changing between shots.

Visible crew/equipment: While Malcolm, Reese, Dewey, and Francis are deliberately making their house messy, you can see right above their ceiling a bright light shining down and a black background. It shows that they film their interior of their house on a set.

Continuity: When Malcolm is trying to get the TV back to the channel he was watching, he picks up a big remote and finds the channel which the video camera feed is on, but the remote he is holding on the TV is a smaller one. It then cuts back to Malcolm who is moving his hand away from the remote he just put down and it's the bigger one again.

Continuity: In the scene where Lois finds out about Francis escaping, there are three orange mugs hanging from a rack by the phone. When Lois reaches for the phone to call the police, she makes the middle one start swinging. She and Hal sit down, and the end mug has moved from the rack into a box on the kitchen counter. Also, the mugs are hanging still. Towards the end of the scene, the "fallen" mug is back on the rack, and the middle mug is swinging again.

Revealing: At the end, Malcolm speaks to camera with several children moving in the background. One boy doesn't know where or when to move and he tries to speak to someone off camera. In the end he gives up, shrugs his shoulders and walks off.

Continuity: When Julie passes through the kitchen to get Malcolm, Dewey and Egg are in there cleaning the floor they have suds all over the floor, When Julie runs back through after seeing Malcolm in his underwear she slides across the floor, The floor is still completely covered in suds but when she gets up if you look in the background you see the floor with hardly any suds anywhere. She could not have soaked up all the suds when she slid across.

Continuity: When Lois is packing lunch in the blue cooler her hands go from on the side of the cooler to down by her waist in one frame to the next. No time for her to move it.

Continuity: When Lois is in the bath tub soaking after getting upset about the family wanting to go to the funeral. Dewey comes in and ask for juice. When they are on Lois(front view) the suds barely come to the top of her breast. When the show Dewey (side view of Lois) The suds are all the way up to her shoulder.

Plot hole: In this episode Dewey tells Francis that their aunt died from a cat eating her face (or something involving a cat mutilating her face) and we find out this is how she really did die. But then why would it be an open-casket if her face was destroyed?

Continuity: While Dewey stands on the table, Mrs. White (Bea Arthur) dips her finger in the bowl of chocolate and draws a mustache with it on Dewey. In the following shots the chocolate on Dewey's face differs.

Audio problem: Near the end when the family have got back in the car Malcolm says something like "who would have thought a traffic jam could be so cool, we should do this again". Well near the end of the sentence we can see Malcolm's mouth and it isn't moving.

Continuity: When Lois and Kitty Kenarban (Stevie's mom) are at the table in the restaurant, while Hal and Abe sit at the bar, things on the table change position or disappear and reappear between shots. Same thing happens at Malcolm's table with Reese and Stevie.

Audio problem: When the girl Krelboyne is talking loudly, you can see her mouth barely matches anything she's saying.

Continuity: During one of Reese's cooking classes, Hal puts some bread into a toaster. It then cuts to a shot of Reese. When it cuts back to Hal, the toast that pops out of the toaster isn't the same shape as the bread he put in.

Continuity: When they are bowling, Malcolm decides to walk up the alley to make a strike. The shot behind him shows him walking into the lane. When the shot switches to the front, he's walking over the line again.

Continuity: When Francis gets pulled over, his window is open and closed between shots.

Visible crew/equipment: When Lois goes into labour with Malcolm, she runs outside taking Francis and Reese with her. When Francis says, "You're a liar, you're a liar," watch the back window of the car and you will see the camera and camera operator's reflection in the window.

Other: In this episode Malcolm's new teacher begins a league table for the Krelboyne class, and since Malcolm shows that he is better than the whole class, the teacher creates a new highest rank for him which he calls "1 to the 11". However mathmatically, "1 to the 11" is still 1, so it seems rather strange that the teacher would go the trouble, and that none of the class would notice this.

Continuity: When the Tarantula is put on Hal at the zoo, the shot is only of a yellow shirt with the tarantula crawling on it. When the shot changes to where they show the whole Hal, you can easily tell that the tarantula is fake - it is larger than it was and is in a different spot on Hal's shirt.