It is established in Islam that Almighty Allah loves kind treatment in all matters. Therefore, treating animals with kindness is a duty upon Muslims, while torturing them is absolutely prohibited.
Hence, bullfighting is unanimously prohibited, for it involves torturing animals. As for whether it is lawful to eat the meat of these animals or not, if they died before being slaughtered according to the Shari`ah, it is unlawful to eat from their meat, for they are then regarded as carrion. If, following the fighting, they are slaughtered according to the Shari`ah, it is lawful then to eat of their meat. However, it is to be born in mind that the lawfulness of eating from the meat of these animals after being slaughtered according to Shari`ah does not make this fighting lawful in principle; its unlawfulness is still established due to the torture inflicted on these animals during the fighting.
Watching and encouraging bullfighting and the like is, likewise, prohibited, for it is a way of contributing to doing something sinful, and this is regarded as sinful in turn. Furthermore, the income earned from this sport is also unlawful.
All countries in Europe and the rest of the world, except Spain, have banned bullfighting because of the torture inflicted on the animals. Muslims, with all the more reason, are to keep themselves away from this brutal sport, especially that there are many other useful sports that Islam encourages them to participate in.
Dr. Nasr Farid Wasil, the former Mufti of Egypt, states the following:

It is established that Islam calls for showing mercy and kindness to all creatures of Almighty Allah, be they humans or animals. It was reported on the authority of `A’ishah, mother of the believers (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) said: ‘(You know) `A’ishah, Almighty Allah is kind and loves kindness; He, moreover, rewards people for the kindness they show (to humans and animals), unlike the case with tough treatment and any other thing.’ (Reported by Muslim)
It is also reported that the Prophet (peace and blessings be upon him) said: “Gentleness beautifies any affair it is involved in while anything that is not involved in, is blemished.” (Reported by Muslim)
The sport in question is either made to be performed between trained horses and bulls without horsemen involved, or between horsemen or individuals and bulls. Both cases are completely forbidden in Islam, for they entail unbearable torture of the animals involved. In the first case, both sides are not equal in power; their fighting will bring about severe pain for both of them and may even cause death to one of them.
According to the Prophet (peace and blessings be upon him) Almighty Allah will judge between animals on the Day of Judgment and He the Almighty will retaliate upon the horned animal that unjustly butted a hornless one.
In the second case, man will use his reason and spare no effort in devising means for hitting the opponent animal with arrows and causing it pain in order that he may amuse his audience further.
It was reported that Ibn `Umar (may Allah be pleased with him and his father) entered upon Yahya bin Sa`id while one of Yahya’s sons was aiming at a hen after tying it up. Ibn `Umar went to it and untied it, then he brought it and the boy and said to the boy’s father: ‘Prevent your boys from tying birds for the sake of killing them, as I have heard the Prophet forbidding the killing of an animal or other living thing after tying them.’
It was also reported that Ibn `Abass (may Allah be pleased with him and his father) said that: ‘A donkey branded on the face passed by the Prophet (peace and blessing be upon him). Seeing it, the Prophet (peace and blessing be upon him) said: “May Almighty Allah curse he who branded it.” (Reported by Muslim)
Abdullah ibn Ja`far also reported that the Prophet (peace and blessing be upon him) passed by some people who were shooting a ram with arrows. He (peace and blessing be upon him) disliked this and said: “Do not torture animals.” (Reported by An-Nassa’i)
These hadiths and others reported also in this regard clearly indicate that Islam calls for mercy and kindness. Islam forbids torturing animals by beating or killing. Even in the case of slaughtering animals according to Shari`ah the Prophet (peace and blessings be upon him) said: “Allah Almighty has ordained you to do everything in the best way. So when
you kill or slaughter an animal, do that in the best way; one of you is to sharpen his knife (before slaughtering) and make the animal lay down.” (Reported by Muslim and Abu Dawud)
Based on the above, whoever encourages bullfighting and calls for it being practiced for the sake of temporary entertainment is sinful and will suffer severe punishment for this sin on the Day of Judgment.
Even if the fighting did not lead to the death of the animal, the pain caused to it is sufficient to render this act sinful. Whoever participates in such a sinful matter will be brought to account for it before Almighty Allah on the Day of Judgment.
Torturing animals does not necessitate shedding their blood. According to the Prophet (peace and blessings be upon him) a woman entered the Fire because of a cat that she had imprisoned till it died of starvation. Bear in mind that the woman did not kill the cat; she only imprisoned it.
Slaughtering the bulls that have participated in the bullfighting according to the Shari`ah and distributing their meat as sadaqah among Muslims, is lawful. But this lawfulness does not render the fighting itself lawful; the unlawfulness of the fighting is still established due to the torture inflicted on the animals. However, should one slaughter a bull as sadaqah, he should do so principally without exhibiting it in a painful fight.
Muslims must not participate in brutal sports of this kind at any rate. There are many other useful sports that Islam encourages them to participate in. They are to bear in mind the hadith of the Prophet (peace and blessings be upon him): “The Most Merciful shows clemency to the merciful among people. (O people!) Show mercy to the creatures on earth, so that He Who is in Heaven shows mercy to you.”
Watching bullfighting and encouraging it in any way is also forbidden, for it is a way of contributing in doing something sinful, and this is sinful in turn. Likewise, money earned from this sport is unlawful.