I want to know what the Islaamic rules are about being a vegetarian. Is it allowed to be a vegetarian or not? I know some Muslims who are vegetarian and they say that it is better to be vegetarian. And they give as reason that there is no such Halaal meat anymore in the world, nowadays. I think it's wrong but please help me. I don't know for sure.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

Saying that there is no lawful (Halaal) meat in the world, is only said by an insane and a mentally deranged person. As there is lawful meat even in western countries where there are Muslims who slaughter animals according to Islamic rites.

If a person is a vegetarian and does not eat meat while believing that it is not permissible to eat the meat, then this is an innovation in religion. Allaah says (what means): {Say, “Who has forbidden the adornment of [i.e. from] Allaah which He has produced for His servants and the good [lawful] things of provision? Say, “They are for those who believe during worldly life [but] exclusively for them on the Day of Resurrection.”} [Quran 7:32]. Allaah also says (what means): {It is He Who created for you all of that which is on earth.} [Quran 2:29]

But if it is a way of treatment and it is the doctors who determined it, then there is no harm as the Prophet said: "O slaves of Allaah, seek treatment." [At-Tirmithi]

Allaah Knows best.