Much of the focus in Jewish tradition regarding death revolves around returning the body to the earth in a consecrated Jewish cemetery as quickly and naturally as possible — again, a respectful appreciation that death is a natural part of life. That’s why the first thing that a Jewish community traditionally does when establishing itself in a new community is to consecrate land as a Jewish cemetery.
Embalming the body — which slows the decomposition process — is out. Being buried above ground is out, although many rabbis agree that crypts and mausoleums are okay. Also, Jews don’t use make-up to make the deceased look more lifelike.
Cremation is definitely out for traditional Jews, who tend to consider it as terrible as committing suicide (many rabbis won’t even officiate at a funeral if the body was cremated). Perhaps early Jews were simply trying to draw a clear distinction between Judaism and pagan religions that customarily cremated their dead.
Many Jews are sensitive about cremation because it draws up images of the Holocaust. Whatever the case, many more liberal Jews choose cremation, though some also request that their ashes be buried so that a tombstone can be erected, allowing friends and relatives to later return to mourn.
Jewish tradition is less clear on the topics of autopsies and organ donations. On the one hand, Jews have long held that maiming a body (even a dead one) is a desecration.
If a traditional Jew requires a limb to be amputated, he or she will often have it buried and then request that it be reburied with the body after death.
Jewish law clearly states that saving another life takes precedence over just about every other principle. So, most rabbis would agree that donating an organ to save someone else’s life is a mitzvah. Many rabbis argue that Jews should avoid autopsies unless they’re vitally important. Ultimately, all these decisions are private and should be discussed with a rabbi on a case-by-case basis.