Shafaqna (Shia International News Association) – The Grand Ayatollah Sistani answered some questions regarding Organ donation.According to Shafaqna the questions and answers are as follows:
Question: If an organ of an atheist is transplanted in a Muslim’s body, would it be considered ritually pure (tãhir) when it is considered, after transplantation, as part of the Muslim’s body?
Answer: An organ extracted from the body is ritually impure (najis) irrespective of whether it came from a Muslim or a non-Muslim. And when it becomes, by rejuvenation, part of a Muslim’s body or of someone who is considered a Muslim, it becomes tãhir.
Question: Are we allowed to donate our organs upon our death? For example our heart, liver, kidneys? Is the soul still attached to the body once we are dead, or is that not true?
Answer: It is permissible, but it is not permissible, as a measure of precaution, to cut an organ of a dead Muslim if he bequeathed, unless a Muslim’s life is in danger.
Source: Ayatollah Sistani