Problem statement: Vitrification is replacing conventional slow freezing to cryopreserve gametes and embryos especially for in vitro production of embryo in domestic animal species. However, the results are still not satisfactory. The aim of this experiment was to study the effect of different equilibration temperatures on in vitro viability of immature bovine oocytes after vitrification. Approach: Oocytes were obtained from slaughterhouse ovaries. Only grade one oocytes were used. Oocytes were equilibrated in three different temperatures: 32, 37, or 41