The dramatic increase of gamete donations, as a result of technological advances in assisted reproduction, has raised considerable legal and halachic issues. This article raises reader awareness about problems involved in gamete donation within Jewish law (halacha), particularly in Israel. Two core problems with gamete donation are: deciding the mother of the child (donor or birthing mother) and genetic lineage. The former is important in establishing the child's religious status and the latter for matters of consanguinity and incest. Anonymous gamete donation increases the probability of incest. Persons unaware of their biological heritage could unintentionally cohabit with a close family member and progeny of this union would be considered mamzerim. These problems may be prevented by legislation, registration, and greater openness by the donor and the intended parents of the donor conceived child. This article focuses on the halachic perspective of gamete donation. Since consanguinity is prohibited by most cultures, the implications of gamete donation are universally relevant.