Girls and young women who require ovariectomy or cancer therapy may consider having their own eggs, embryos or ovarian tissue stored (cryopreserved) for their own future use. Ovarian tissue is simple to collect and contains large numbers of germ cells. Transplantation of fresh and frozen-thawed ovarian tissue in healthy sheep and mice has resulted in normal live young. Similar techniques may be effective in the human but it is unclear whether ovarian tissue cryopreservation and grafting is suitable for ovaries from individuals with cancer or infections. If cancer cells were present in an ovary at the time of collection and survived cryopreservation and grafting they could establish cancer in the recipient. We therefore performed ovarian cryopreservation and transplantation trials using a mouse lymphoma model. This established that the lymphoma was transmitted by grafts of both fresh and frozen ovarian tissue. The normal healthy recipient mice died 9-43 days after receiving a small piece (1 mm3) of ovarian tissue from a donor with lymphoma. We conclude that ovarian tissue which is collected, cryopreserved and grafted while it contains cancer cells has the potential to spread the cancer to the graft recipient.