Human T-cell lymphotrophic virus (HTLV)-1 has been reported after solid-organ transplantation, with a related fatal outcome in less than five cases. The natural history of HTLV-1 transmission from donor to recipient is unknown in this setting, because available screening platforms are suboptimal in low-prevalence areas and there is a lack of long-term follow-up. Minimizing organ wastage due to false-positive screening and avoiding donor-derived HTLV-associated diseases remain the goal. To date, only six HTLV-naive organ recipients from four donors (only one had confirmed HTLV) have developed HTLV-associated disease after transplantation. All of these cases were described in countries or from donors from HTLV-endemic regions. To the best of our knowledge, there have been no reported cases of donor-derived HTLV-1–associated death after organ transplantation in the world. Based on data from low-prevalence countries (Europe and the United States) and the current shortage of donor organs, it appears plausible to authorize the decision to transplant an organ without the prior knowledge of the donor’s HTLV-1 status. Currently, it is not possible to exclude such transmission and recipients should be informed of the possible inadvertent transmission of this (and other) infections at the time of consent. In those cases where HTLV-1 transmission does occur, there may be a therapeutic window in which use of antiviral agents (i.e., zidovudine and raltegravir) may be of benefit. The development of national/international registries should allow a greater understanding of the extent and consequences of transmission risk and so allow a more evidence-based approach to management.