Objective: To report tow cases of successful pregnancies following long term cryopreserved spermatozoa prior to bone marrow transplantation (BMT) for chronic myelogenous leukemia (CML) and severe aplastic anemia (SAA). Materials and Methods: Case report. Results: With the first case, after cryopreservation of semen from 25 year-old man with CML prior to BMT, his wife is being pregnant by intracytoplasmic sperm injection (ICSI) using thawed spermatozoa. With the second case, 28 year-old man with SAA became father by ICSI using banked spermatozoa before BMT. Conclusion: These cases support that men with malignancy have the chance of fathering their own genetic children. It is important therefore, to increase the awareness of clinicians especially oncologists and patients themselves to the new developments in preserving fertility for cancer patients.