Donor-derived disease transmission is increasingly recognized as a source of morbidity and mortality among transplant recipients. Policy 4.7 of the Organ Procurement and Transplantation Network (OPTN) currently requires reporting of donor-derived events. All potential donor-derived transmission events (PDDTE) reported to OPTN/UNOS were reviewed by the Disease Transmission Advisory Committee (DTAC). Summary data from January 1, 2005-December 31, 2007, were prepared for presentation. Reports of PDDTE have increased from 7 in 2005, the first full year data were collected, to 60 in 2006 and to 97 in 2007. More detailed information is available for 2007; a classification system for determining likelihood of donor-derived transmission was utilized. In 2007, there were four proven and one possible donor-derived malignancy transmissions and four proven, two probable and six possible donor-derived infectious diseases transmissions. There were nine reported recipient deaths attributable to proven donor transmissions events arising from eight donors during 2007. Although recognized transmission events resulted in significant morbidity and mortality, transmission was reported in only 0.96% of deceased donor donations overall. Improved reporting, through enhanced recognition and communication, will be critical to better estimate the transmission risk of infection and malignancy through organ transplantation.