The Taurus that crashes into the limo at the beginning of the movie is seen soaring down the road with lots of people in it, two of them hanging out of the sunroof. At the instant of the impact between the two cars there are no people out of the sunroof - as a matter of fact there is nobody in the car.

At L.A. Airport, while Betty waves at the old couple, you can spot the taxi cab over her shoulder. We see the driver open the trunk, but when she turns around looking for her bags, it's closed again... and then he re-opens it to put her suitcases inside.

Explanation: This sequence originally got shot with Betty turning to the cab driver before waving at the couple, yet left the cutting room in reversed order.

At Ryan Board, when Vincenzo Castigliane slides the envelope with the photo of Camilla Rhodes down the conference table, the flap on the envelope is up when it leaves Vincenzo's hand, but the flap is down when the envelope arrives at the other end of the table and is retrieved by Ray and Mr Darby.

The envelope retrieved by Mr Darby is somewhat crinkled and the flap is free of marks. However, at close-up we see an envelope in better shape with a flap that's got a hole punched-in.

Explanation: The original headshot of Camilla Rhodes, intended for the TV-Pilot, had been replaced for the feature film. The newly shot close-up lacks perfection in terms of continuity.

When the servant comes in to serve the cup of espresso, Luigi's hands and arms are on the table, then the very next shot, they are tucked under the table, then back again.

The headshot of Camilla in front of Vincent Darby seems to disappear for a second, just after Luigi expels his coffee. 

After Joe shoots Ed, we see an unstained "Italy" poster to the right of the desk. When Joe drags the fat woman into the office, there is now blood dripping down the poster.

Explanation: Lynch might have mixed censored with non-censored footage of the hit on Ed. From the Pilot script:
"Joe's hand [...] reaches out and fires a hole through Ed's temple - blowing Ed's brains out across the desk, carpet and wall." 
»see also Trivia of Massacre scene

The office next door with the Enzyme woman in it has a large sticker on the outside window (facing out) that says Enzyme + Plus. From the outside shot there is no sign in the window.

Right after Betty is talking to her aunt, she walks into the bedroom to confront Rita. Rita is sitting at the foot of the bed and there is no towel to her right. The camera cuts back to Betty and when it shows Rita again, there is a red towel on the bed beside her. Also, the pillows seem to have moved against the earlier front-view shot. 

A perceptive contribution to the complexities of David Lynch's dream narrative?

Betty takes the hat out of the box and holds it. After Rita puts her bag with the money in the box, we see Betty lifting the hat from the bed and putting it inside the box, although it should still be in her hands.

When they hide the purse with the money and the key in the round hatbox, Betty places the hat on top and then puts the box in the closet. When they retrieve the purse after returning from the Club Silencio, the hat isn't there.

Explanation: The Pilot script contains a canned scene, where Rita opens the hatbox and removes the purse to handle over some money to Betty in return for her kindness. Thereby hat and purse might have switched positions. 

When Betty arrives at her audition her necklace isn't showing, but when we see her again her necklace is right there.

An error sequences appears after Wally says "let’s everyone take a seat". Right facing megaphone under Wally’s Emmy award (in background) changes to face left between shots.

In the scene where Betty and Rita are kissing in bed, their head tilt changes direction between shots.

In the scene following Club Silencio Betty places the blue box onto the bed next to the red blanket and … disappears. Rita pulls out her purse from the hatbox, places it onto the red blanket and leaves to look for Betty. Upon her return the blue box has considerably moved away from the red blanked.

In the scene where Rita turns the key in the blue box, the position of the keyhole changes between shots.

1. Rita glances at the box sitting on the bed. *cutaway*

2. She takes the box into her hands. *cutaway*

3. Rita turns and removes the key. The keyhole is back to its original position 1, as if she never turned the key at all. *cutaway*

4. Rita reaches for the box to opens it. Now the keyhole is in just another position.

On the couch, Camilla grabs at Diane's shoulder to stop her. Diane clinches Camilla's forearm with her left hand. In the cut-over to Diane her hand is off Camilla.

In the final scene, when the elderly chase Diane into the bedroom, Diane falls onto her bed with two pillows sitting on it. After a cut-over to the elderly the camera pans across the bed again and this time we only see one pillow.

Factual error: After the hitman Joe shoots Ed in his office and is placing the gun in Ed's hand, it discharges and shoots a hole in the wall. The appearance of the wallpaper around the hole makes it look more like an exit hole than an entrance hole.

Factual error: Guest room doors in Hotels open into their respective rooms not into the hallway. Therefore, Adam is behind a door painted number 16, it is just not a hotel room.

Revealing mistake: When Adam goes to meet the Cowboy and he's just coming closer to the parking position, you can see a spot of lighter sand/ground, which is shaped exactly like the car. Looks like the car left a dry patch after it had been raining.

Factual error: When Betty puts the coins in the payphone outside Winkie's to call the police department, the coin return lever is flipped down. A coin will not go into a payphone when the lever is depressed.

Crew or equipment visible: During the long tracking shot of the mob goon (Kenny) entering the director's house a crew member is reflected in the window.

Crew or equipment visible: As Adam walks to the Castiglianes' limo you can see the film crew in the window across the street.

Factual error: When the two detectives are looking at the car wreck, one says "We found these in the back seat of the Caddy." The car is actually a Lincoln.

Explanation: Mixing up car brands could just indicate Diane's ignorance in technical matters. »see also Abraham Lincoln connection

Continuity: In the last shot of Adam beating the Castigliane brothers car with a golf club, we see a flock of birds fly from behind the car in a scare. It's impossible they've stayed there during the whole beating sequence and we don't see them land anywhere near the car during the sequence itself.

Audio/visual unsynchronized: Having just gotten off the phone with her aunt, Betty comes into the bedroom. We hear a small click as the door knob is touched or pushed and then a very loud twisting of the doorknob, but only after the door has started swinging in.

Audio/visual unsynchronized: When Betty is using the pay phone outside Winkie's, the touch tones are audible before she touches the keypad.

Factual error (possibly deliberate error by the filmmakers): Betty exits LAX at Departure rather than Arrival level. 

Factual error: When Betty tries to call D. Selwin ("it's strange to be calling yourself"), it looks like she forgets to hit the CALL key.