Background: Fertility preservation refers to a procedure performed to maintain the ability to become pregnant before receiving treatment with a risk of fertility loss, such as chemo- or radiation therapy. Examples of fertility-preserving procedures include freezing, sperm freezing, embryo freezing through <i>in vitro</i> fertilization, and ovarian tissue freezing.Current Concepts: Until the late 1990s, awareness of fertility preservation among clinicians and patients was relatively low, and the only way to preserve and restore fertility in women with cancer was the cryopreservation of embryos. However, as the survival rate of cancer patients increased and the treatment results of various diseases improved, interest in quality of life such as pregnancy and childbirth after treatment gradually increased, and became a driving force for the development of fertility preservation. In the 2000s, several centers began cryopreserving ovarian tissue, including primordial follicles from young patients before chemotherapy. Currently, ovarian tissue cryopreservation can be used in combination with <i>in vitro</i> maturation and egg vitrification techniques. Novel methods to improve follicle survival after transplantation are currently being investigated. Methods to improve follicle survival after transplantation and new ovarian protective agents to protect the ovaries from cytotoxic agents are currently being studied.Discussion and Conclusion: Advances in fertility-preserving technologies in the future will contribute to the delivery of healthy children by providing tailored treatments and more individualized fertility-preserving strategies to patients whose fertility is at risk.