Sperm banking is the recommended standard of care for men freezing their sperm for a variety of reasons, including treatment for cancer. It is recommended in all men of reproductive age including adults and adolescents diagnosed with cancer before the start of cancer treatment. Sperm banking is also increasingly used for posthumous sperm-retrieval requests, for patients traveling to areas affected with the Zika virus, patients with HIV, and men undergoing gender reassignment. Protocols for sperm freezing, including conventional slow freezing, vitrification, and use of home sperm-banking kit, are described. This chapter also discusses the use of testicular tissue sperm cryopreservation for sperm banking. Furthermore, legal and ethical issues associated with sperm banking, techniques to improve sperm-banking outcomes, and use of sperm banking in assisted reproductive techniques (ART) are also discussed in the chapter.