I know in "American Pie 2" there's a scene where the milf guy takes a piss over the balcony. You don't actually see him doing it, but you do see the piss raining down.

Also in the horror movie "Pieces", you see a woman piss in her pants as the killer stalks her.

Any other movies that show or imply a character urinating onscreen?

I apologize if this topic offends anyone.

This is a weird topic but David Lynch's Wild At Heart has a scene with a man urinating IIRC

Jeepers Creepers and Jeepers Creepers 2 both have urination scenes.

Wild Zero has a urination scene, and the camera angle places you right above the organ doing the peeing.

Tommy Boy. The scene where that guy pees on the power system.

oh yeah, Bicycle Thieves has a urination scene with Bruno peeing on the side of a building.

Shaolin Soccer has the down-on-his-luck coach urinating on a wall.

Kung Fu Hustle has a scene where some kids beat a younger kid up, then pee on him.

Swingers has a scene with Vince Vaughn peeing on the side of the road on the way home from Vegas.

Labyrinth has a scene of the dwarf peeing of a bridge.

Innerspace has a scene with Martin Short peeing while talking to Randy Quaid inside him.

The Ref has a shot of a drunk Santa pissing in the bushes.

Dirty Rotten Scoundrels has Steve Martin asking to go to the bathroom.

In Unforgiven, the writer pisses his pants we he first meets Gene Hackman.

Dirty Work has a charater pissing off a building.

In Tommy Boy, Tommy's "step-brother" urinates on the electric generator thing and it zaps him.

In The Green Mile, Tom Hanks' character has an urinary infection and is seen on screen a couple time painfully urinating. Also, in the same movie, the kid who tries to act tough gets scared and urinates in his pants.

In Dumb & Dumber, Jim Carrey's character has a scene where he is urinating in a bottle and he can't stop going. He eventually fills up like half a dozen bottles.

In Austin Powers, after being cryo-frozen for 30-some years, Austin is thawed out, and one of the first things he does is take a really long urination.

In Revenge of the Nerds, Ogre has a scene where he urinates throughout the entire scene which is around 4-5 minutes long.

In Deep Blue Sea, one of the scientists urinates into the wind.

Apollo 13 - unine in space!

History of the World Part I
Prospero's Books
Jason goes to hell
*Big
Up in Smoke
Jungle Holocaust
The Package
*The Money Pit
Lethal Weapon
Sixth Sense
Last House on the left
Greystoke:The Legend of Tarzan
Innerspace
Psycho III
Revenge of the Nerds 2
*The Green Mile
Tie me up! Tie me down!
Gridlock'd
House on the edge of the park
Above the rim
Caligula
Meatballs 3
The Man Who Fell to Earth
Posse
Crocodile Dundee 2
Cannibal Holocaust
Tubby The Tuba (First time I've seen an animated dog pee)
Young Guns
*Castaway

*I noticed that Tom Hanks does it a lot

the Big Lebowski "you peed on my rug"

End of Days...Gabriel Byrne

BOOM!!!!

The Loss of Sexual Innocence

Big Daddy.

"What's your name? He'll write it on the wall for you."

Or some such nonsense.

Ransom
Three Men and a Baby

In Empire Records, Robin Tunney takes a whiz after tending to Liv Tyler after her freakout.

Just watched "Fistful of Dynamite" AKA "Duck, You Sucker" and the film starts with a shot of piss being applied to ants, possibly on a tree IIRC.

Did the "Wild Bunch" have a piss scene?

strange brew

take off eh?

I was once taught that "You ain't cool, unless you pee your pants."
That same movie also taught me that Miss Vaughn was a nice piece of ass.

The 40-Year-Old Virgin

"I CAN'T DO IT IN PUBLIC!"

Transamerica
The Usual Suspects

You forgot "A League of Their Own"

And as much as I'd like to forget it, there's Kevin Costner in the opening scene in Waterworld.

Life as a house .. Kevin Kline

Kate Winslet in Holy Smoke
Linda Blair in The Exorcist
Nicole Kidman in Eyes Wide Shut
Isabelle Huppert in The Piano Teacher
Victoria Abril in Tie Me Up, Tie Me Down
Carmen Maura in Women On The Verge Of A Nervous Breakdown