Jackie Chan's very worst injury ever, the one that almost killed him, actually occurred on very routine stunt. He was shooting Armour of God in Yugoslavia, and was still recovering from the jet lag of flying twenty hours to get there. The stunt was simple -just jumping down from a castle wall to a tree below. The first time he tried it, the stunt went perfectly, but he wasn't satisfied with the take. He tried it again, a second time, he somehow missed the branch he was trying to grab. Wish! He fell past the tree and onto the ground below. He hit the rocky ground head first. A piece of his skull cracked and shot up into his brain, and blood poured from his ears. The production team quickly got on the phones to try to find the nearest hospital that could do emergency brain surgery, and eight hours later, he was under the knife. The operation was successful, and he recovered quickly -even though there's a permanent hole in his head now, with a plastic plug there to keep his brains in.

Source: "Iam Jackie Chan : My life in action"

He was actually knocked uncounsious while working as a stuntmen on Hand Of Death.

His brow ridge was injured and he nearly lost an eye while shooting for Drunken Master

He has broken his Nose 3 times on Young Master, Project A and Mr nice Guy

The Armour of God also left him hard of hearing in one ear

Hwang Jang Lee kicked out one of his teeth (accidently) on Snake in Eagle Shadow

His cheekbone was dislocated during the making of Supercop

He was almost suffocated during the making of Young Master when he injured his throat

His worst neck injuries took place during the making of Project A and Mr. Nice Guy

During the making of City Hunter he dislocated his shoulder

His sterum was dislocated after falling from a hanging chain during Amour of God II operation condour

While shooting for a fight in Snake in Eagle Shadow his arms was accidently slashed by a sword that should have had a blunted edge. blood went everywhere and he fell down screaming and the camera kept rolling that's the real blood scene you see in the movie

He has suffered many back injuries but the worst one was during the making of Police Story in which he broke his seventh and eight vertebrate in his spine

His pelvis was dislocated during the Pole Slide Stunt

His hands and fingers were hurt during Protector

While shooting Crime Story his leg got crushed after getting caught between two cars

One of the worst knee injuries happened during City Hunter while shooting a skateboard chase

While shooting for Rumble In the Bronx he broke his ankle while jumping onto a hovercraft