A bull left at least 40 people wounded on Wednesday, after leaping into the stands during a "recortadores" competition in the northern Spanish city of Tafalla.
The "recortadores" is a tournament in which young boys run before a bull while trying to avoid being gored.
20 people were taken to the hospital once the bull was finally pacified with rope.
One man was gored in the back, and a ten-year-old boy is still in the hospital with several contusions.
Human injuries are nothing new when it comes to bulls.
But it is the harm done to the animals themselves in Spain that has become increasingly controversial in recent months.
In July, the Spanish region of Catalonia banned bullfighting to combat cruelty to animals.
The landmark vote marks the first time the bloody sport has been banned in mainland Spain.