Aim. The aim of this article is to review the evidence regarding human oocyte cryopreservation by slow freezing and vitrification and to provide evidence-based clinical and laboratory guidelines on the effectiveness and safety of these technologies. Scope. These guidelines will address the following: Stage of oocyte maturity. Methods of cryopreservation/warming. Slow controlled cooling. Vitrification. Techniques used for insemination. Ovarian stimulation regimens. The guidelines do not cover recommendations for ovarian tissue freezing or in vitro oocyte maturation (IVM). Outcome measures. The following outcome measures were examined: cryosurvival, fertilisation rate, cleavage rate, clinical pregnancy rate and implantation rate, health of resulting children.