This study compared the predictive value of the LIVE/DEAD fluorescence viability assay to xenotransplantation in SCID mice, regarding the developmental potential of cryopreseved human ovarian tissue for fertility preservation purposes. The thawed ovarian tissue of ten patients was partly examined by LIVE/DEAD viability staining or histologically examined after transplantation and gonadotropin stimulation in 30 SCID mice. The LIVEIDEAD assay showed 87.1 +/- 3.5% (mean +/-SD, n=10) viable follicles (intact oocyte and more than 50% of granulosa cells alive). Histological examination showed follicles in all developmental stages in the transplanted grafts. The total number of follicles found was much lower than with the LIVE/DEAD assay (8.9 +/- 3.1 versus 54.4 +/- 20.0, p < 0.001). If the LIVE/DEAD assay yields > approximately 85% viable follicles, it can be assumed that the follicles in the cryopreserved tissue have maintained their developmental potential. This assay is, therefore, a suitable diagnostic method before an intended retransplantation.