Germplasm cryopreservation is an important ex situ conservation programme to preserve the important animal genetic resources for future use. Cryopreservation processes used for mammalian cells include slow freezing and vitrification with recent shift towards vitrification especially in case of oocytes and embryos as it produces less damage to the oocytes and embryos than slow freezing. Vitrification of oocytes has almost become a standard approach for cryopreservation of female gametes due to numerous efforts like development of novel cryodevice such as OPS or Cryotop which resulted in increasing cooling and warming rates thereby cryosurvival and blastocyst yields of vitrified oocytes. Now attempts are focused on the qualitative improvement of oocytes prior to the vitrification in order to increase their revivability to acceptable levels, to overcome the high sensitivity of oocytes to cryopreservation and to improve blastocyst yield and pregnancy rate. This article is an overview of immature oocytes vitrification and its various aspects as a tool for long term preservation of female germplasm.