Continuity mistake: When the Dude is in Jackie Treehorn's estate, he pencils over a pad of paper to see what Jackie wrote down while he was on the phone. He then hurriedly crumples up the piece of paper and shoves it in his wallet. Then, when we see the Chief of Police of Malibu looking through the contents of The Dude's wallet, the paper is there, neatly folded in fourths.
Continuity mistake: In the opening credits when a very large bowler attempts a 7-10 split, the ball he releases changes color when it is shown picking up the spare.
Continuity mistake: The Dude's driver's-side door is unusable after his car is stolen and retrieved, and we see him using the passenger door at least once after he takes the car home. But then at Larry Sellers' house, which they visit pretty soon, The Dude gets out of the driver's door as if nothing had happened; I doubt he'd have bothered to have it fixed in that short time. (01:09:00)
Continuity mistake: When the Dude first looks at the Nihilist in the pool the liquor bottle is way off to the side. In the next shot a few seconds later, (the close up) it is tucked right under his arm. (00:15:30)
Continuity mistake: When Jesus' partner is seen bowling for the first time, when you see the P.O.V of the bowling pins there's another much skinnier man with different clothes in his place. Then the shot goes back to the Jesus' partner's midsection doing his strike dance. (00:06:20)
Continuity mistake: When they exit the bowling alley with the dog, the dog is never put in the car, only the cage.
Continuity mistake: There's one scene where The Dude is taking a bath, and three Germans threaten him with a marmot (actually a ferret). When they take the little animal out of the water, you see Dude's head and in the back four candles: yellow, blue, red and white. The yellow and red one aren't burning; the blue and white are. The next shot of the Dude's head you see that the yellow, blue and red candles are burning, the white one isn't.
Continuity mistake: When The Dude enters Lebowski's office the telephone is on the far right of the desk and the lamp is on the far left with 3 wooden objects between them. During the shots of The Dude, when he is talking, the phone and lamp are much closer together and the wooden objects aren't there. (00:12:00)
Continuity mistake: When you first see the Dude, Walter, and Donnie together at the bowling alley the bowlers sitting in the background of the next lane keep changing between the shots of Walter and Donnie sitting down and the Dude standing. (00:09:00)
Continuity mistake: When the Dude shows up at Maude's place (the time where the video artist is laughing annoyingly), pay attention to Maude's bangs changing positions between several shots. Sometimes the hair is raised up on the left side of her forehead and other times the bangs are straight across. It's most noticeable after she pours a drink and turns around.
Continuity mistake: In her studio, Maude dumps a bunch of trinkets on the counter. While she is on the phone, some of the items disappear and then reappear.
Continuity mistake: When the Dude joins Mr. Lebowski in the West Wing, where he was in seclusion, he is handed Bunny's ransom note by Brandt. As he reads the note he smokes a joint. Through the entire reading sequence he moves the joint from his mouth to his hand and back. Watch how several times the joint is in his hand, while you see a shot of the note and the Dude's hands, but when the shot changes to overall view, the joint is suddenly back in his mouth and he retrieves it again.
Continuity mistake: When the Dude's driving home from the doctor's, he passes a yellow truck, visible through the side window, when he throws his joint against the door window. If you compare the shot where he grabs for his joint and the next one where he sprinkles the beer, you'll see he passes the truck twice. (01:05:35)
Continuity mistake: When Lebowski is driving home from the doctors office, the back window of his car is so covered with dirt that you cannot see out of it, yet when he looks in his rearview mirror there is a very clear reflection of the car following him. (01:05:00 - 01:16:00)
Continuity mistake: In the porno film that Maude shows to the Dude, Karl is seen driving a BMW 318i convertible in the E36 generation. This particular model didn't come out until 1994.
Continuity mistake: When the Eagles-loving cabbie goes to throw the Dude out of his cab, a black Nissan Maxima passes by the cab. This particular model didn't come out until 1995.
Continuity mistake: The cab belonging to the Eagles-loving cab driver has the same California license plate as Mr. Lebowski's limo. (00:47:05 - 01:23:00)