The Jewish restrictions on autopsy come from biblical laws and Talmudic interpretation.
The Jewish restrictions on autopsy come from biblical laws and Talmudic interpretation.

Judaism is against autopsies overall, and observant Jews generally consider them forbidden. However, because Jewish tradition usually tries to address every possible variant of a situation, the laws prohibiting autopsy have some flexibility. Depending on the purpose of the procedure, an autopsy may be permitted under Jewish law in some circumstances, even in very observant communities.

Jewish Law

Jewish law forbids anything that desecrates or disgraces a corpse. Not only does the process of autopsy do so, but delaying burial does as well, and performing an autopsy takes time. For a burial to be in accordance with Jewish law, the entire body must be buried, so Jews can't properly bury a body which has had parts or fluids removed during autopsy. Jews also believe that a person's body does not belong to him but to God, and therefore people have no right to perform an autopsy on what is essentially God's property.

Exceptions to the Rule

One of the highest and holiest laws in Judaism is pikuach nefesh, or saving a life. If performing an autopsy might save another life, it is considered pikuach nefesh and therefore permissible. For example, if someone dies of a mysterious illness from which others are also suffering, doctors may perform an autopsy on him to learn more about the illness and potentially save the other lives. However, the doctors must have reasonable expectation that they'll need this information in the near future; the mere possibility that an autopsy might yield information that will be useful somewhere down the line is not sufficient to make the autopsy permissible under Jewish law.

Making Autopsy Acceptable

Even if the procedure is likely to save lives, Jewish custom requires that doctors treat the body with utmost respect during an autopsy. Only the relevant areas of the body should be cut or examined, and the rest of the body should be covered modestly. Doctors should perform the autopsy as promptly as possible so the body can be buried quickly. Unless the doctor is himself an observant Jew who understands the laws surrounding autopsy, a rabbi should observe the procedure. The doctor must keep all the body parts and fluids so the entire body can be buried.

Permissions Given

Despite the laws regarding burying the whole body, blood samples and small biopsies are permitted after death and don't qualify as disgraceful to the body. Endoscopies and laparoscopies are also acceptable. Even if there is no medical reason to perform an autopsy, Judaism permits it if it's necessary to identify a murder victim's killer or to identify the deceased himself. While Orthodox and Conservative Jews follow the traditional restrictions on autopsy, Reform Jews consider any advancement to medical science to be pikuach nefesh, and therefore the Reform movement believes autopsy for medical research to be permissible.