**Abstract**

Gamete cryobanking has been widely incorporated in present assisted reproductive technology (ART). Preserving male gametes for future fertility is considered to be an easy and accessible way to insure one's reproduction. Despite the fact that the method could not secure success, sperm freezing could be the only chance to father biological offspring. In cases when severe male factor (SMF) infertility is diagnosed (retrograde ejaculation, virtual azoospermia, obstructive azoospermia, cryptozoospermia) and providing fresh semen samples for assisted reproduction may alter chances to achieve pregnancy, rare sperm cryopreservation could contribute for conceiving. Isolation, selection and cryopreservation of single sperm cells from semen samples is a challenging procedure. Different approaches and devices could be used in order to extract utmost spermatozoa. Aiming to highest cryosurvival rates sperm freezing protocols should be carefully considered. For some men, rare sperm cryopreservation might be the only alternative for parenting biological offspring. Thus, the latter technique should be widely discussed, developed and practiced in assisted reproduction.

**Keywords:** cryopreservation, fertility preservation, single sperm selection, sperm sorting devices, cryptozoospermia, sperm genetics
