Preservation of female fertility is an important issue today. However, there are few effective clinical options for preserving female fertility. Firstly, conventional in vitro fertilization (IVF) followed by embryo cryopreservation is an accepted procedure but is not applicable to all women. Embryo freezing is suitable only for women with a male partner and may not be acceptable to some patients due to moral and religious reasons. Ovarian tissue freezing is another option of female fertility preservation but is an invasive procedure and the efficacy of this technique remains to be determined. Oocyte cryopreservation is also method for fertility preservation. Egg freezing is mini-mally invasive and can avoid the ethical and moral concerns related to cryopreservation of embryos. However, conventional slow freezing/rapid thawing methods are associ-ated with low survival of oocytes. Recent development in vitrification of oocytes appears promising. Therefore, vitrification of unfertilized eggs may be a novel method to preserve female fertility. Preservation of female fertility is an important issue today. However, there are few effective clinical options for preserving female fertility. Firstly, conventional in vitro fertilization (IVF) followed by embryo cryopreservation is an accepted procedure but is not applicable to all women. Embryo freezing is suitable only for women with a male partner and may not be acceptable to some patients due to moral and religious reasons. Ovarian tissue freezing is another option of female fertility preservation but is an invasive procedure and the efficacy of this technique remains to be determined. Egg freezing is mini-mally invasive and can avoid the ethical and moral concerns related to cryopreservation of embryos. However, conventional slow freezing / rapid thawing methods are associ-ated with low survival of oocytes. Recent development in vitrification of oocytes appears promising. Therefore, vitrification of unfertilized e ggs may be a novel method to preserve female fertility.