Sheitels are wigs rabbincally certified for wear by married Jewish women so as to conform with religious stipulations for feminine modesty in appearance and behavior. The theory is that this most treasured part of a woman, her hair, symbolizing her beauty and sensuality, should be reserved for her husband. Most often used by the Orthodox and Ultraorthodox, Sheitels are fully compliant with all halachic requirements but some Hasidic sects actually forbid their wear as they can give the appearance that the woman's head is actually uncovered. Indeed, almost half of the observant married women in Israel do not wear such wigs because their rabbis have deemed them insufficiently modest. Thus they may also wear a snood, an additional head covering distinct from the wig, or some other headgear that totally hides the hair.

Sheitels can be very expensive, as they are most often 100% human hair wigs. The main types of hair used for Sheitels come from Eastern Europe or Asia. Asian hair is often treated chemically for color and texture, whereas European hair is often left alone, thus acquiring the label of "virgin" hair. Of the two, European hair is by far the more expensive variety, though even synthetic hairs can cost a pretty penny as well, depending on several sundry factors.

In order to be considered kosher, Sheitels need to meet many strict requirements, some of which can be fairly difficult to ascertain, as exemplified in 2005 by the controversy that erupted over rumors concerning human hair from India. The fear was that these hairs had previously been used for the worship of idols. Such associations would render the Sheitels unclean and thus not fit for the observant Orthodox, as there is an old dictum that no benefit can come of anything used in idolatry.

But this issue is a rather old one in many respects, as the matter had been raised fifteen years previously in 1990, when it was questioned whether hair shorn during religious ceremonies in India are to be considered materials dedicated to idol worship. A religious inquiry ensued that, after much examination, found nothing wrong with the situation. The 2005 case stirred another investigation, which concluded that misunderstanding of theory and practice was again behind the concerns. However, on account of all the consternation raised, most wigmakers now refrain from using Indian hair, and a lot of the Asian hair used these days come from China, particularly the westernmost parts where it is said that the people are more racially or ethnically closer to Europeans.