BACKGROUND AND OBJECTIVE: Cryopreservation of sperm currently plays a significant role in maintaining the fertility of couples who undergo infertility treatment, particularly in patients with oligospermia and cryptospermia. To avoid recurrent biopsies, we need to dedicate a lot of time to sperm collection so that the patient is placed in infertility treatment cycles when the necessary conditions are provided. This study is dedicated to Cryopreservation of sperm in oligospermia and cryptospermia samples.

METHODS: For this study, we referred to NCBI database and selected articles related to various methods of cryopreserving sperm using certain keywords such as "oligospermia", "cryptospermia" and "cryopreservation of sperm" and articles that surveyed cryopreservation in terms of medical and functional views.

FINDINGS: To cryopreserve sperm, three methods are used; slow, fast and glass. Using several preservatives in culture medium is necessary for survival of sperm. Since cryopreservation may weaken sperm mobility in patients with severe spermatogenesis disorder, researchers seek to devise new methods to reduce these effects. Using zona pellucid, volvox globator algae, alginate-agarose, cryoloop, straw and microinjection needle are among the methods advised for preserving sperms and increasing their survival rate.

CONCLUSION: According to the results of this study, using different tools to achieve best results depends on the type of samples obtained from these patients.