Visible crew/equipment: When the rear of the truck explodes after Will Smith shoots it, the pipes that feed the scene with smoke can be seen just above the kerbstones.

Other: In the final scene outside the MIB headquarters, Kay opens the neuralizer and we see it open, but there is no sound. Later when Kay tells Jay that he hasn't been training a partner but a replacement, we hear the sound of the neuralizer opening and Kay tells Jay how to operate it.

Revealing: In the scene after J shoots the exterminator van off of the tow truck he shoots again. When the camera clips to the tow truck driving away, you can see the smoke generators emitting smoke from the curb.

Continuity: After Kay neuralizes Jay the first time, Jay 'wakes' up in a restaurant and Kay hands Jay a card. He tells him to report to that location. The address can be seen written on the back on the bottom edge of the card. Jay flips the card over to read the address and it's still on the bottom edge of the card. When flipped, the address should now be on the top edge of the card.

Continuity: When Will Smith and the other recruits are taking their written tests, the white table first appears to be situated between the second and third men from the left. When Smith goes to the table to pull it across the room, it is much further to the right of the scene.

Continuity: In the begining of the film when "Edgar" kills the exterminator, the exterminator's truck has a small almost unnoticable plastic roach decoration on top. Yet during the rest of the movie the roach is huge and it sticks up away from the vehicle.

Continuity: In the scene when Tommy Lee Jones and Will Smith are walking through the hallway right after they're done with the gun test where Smith shoots the little girl, Tommy Lee Jones says "this way" and they turn into the hallway. If you look closely on the right side of the screen, you can see the door that leads to the shooting test, which shows that it's the same hallway that they passed through before.

Continuity: In the scene where Zed sends Kay and Jay out on Kay's first mission, Reggie's unauthorised departure from Manhattan, Tommy Lee Jones legs cross and uncross from shot to shot.

Continuity: The MIB applicants are all sitting in the testing room and Zed talks about how they are all the best of the best of the best like, "Rangers, Navy SEALs, NYPD".   The only sailor sitting in the room is not a SEAL, he's EOD.  You can tell because he is not wearing the Special Warfare badge on his uniform, he's wearing the badge for Explosive Ordnance Disposal.

Revealing: In the scene where Edgar's skin gets inhabited by the alien bug, and goes back into the house, he pulls his skin back to make it stop hanging from his bones, in the next shot, he appears to still be holding it back, but when he lets go, it is very apparent that he was only holding his hair.

Continuity: When J and K are shooting their guns at the space ship toward the end, if you look carefully, you can see the spark that ignites their guns to have the fire come out of the barrel.

Continuity: When Will Smith & T. Jones are going to the jewellery store the bug/Edgar is pointing the shotgun at the tow truck person. How come K & J don't notice that?