Cryopreservation of dog semen is an assisted reproductive technology of the utmost importance for increasing the genetic pool and developing the dog breeding industry. This technique is not unharmful for the sperm, and factors such as extender, cryoprotectant, and cooling-warming rates have been shown to affect the after-thawing quality of canine sperm. This chapter aims to describe the current range of methodologies available that are key to ensure successful freezing and thawing of dog sperm.