The purpose of this study was to evaluate the incidence and etiology of bacterial and fungal infection or contamination in lung allograft donors and to assess donor-to-host transmission of these infections. Recipients who survived more than 24 h and their respective donors were evaluated. The overall incidence of donor infection was 52% (103 out of 197 donors). Types of donor infection included isolated contamination of preservation fluids (n = 30, 29.1%), graft colonization (n = 65, 63.1%) and bacteremia (n = 8, 7.8%). Donor-to-host transmission of bacterial or fungal infection occurred in 15 lung allograft recipients, 7.6% of lung transplants performed. Among these cases, 2 were due to donor bacteremia and 13 to colonization of the graft. Twenty-five percent of donors with bacteremia and 14.1% of colonized grafts were responsible for transmitting infection. Excluding the five cases without an effective prophylactic regimen, prophylaxis failure occurred in 11 out of 197 procedures (5.58%). Donor-to-host transmission of infection is a frequent event after lung transplantation. Fatal consequences can be avoided with an appropriate prophylactic antibiotic regimen that must be modified according to the microorganisms isolated from cultures of samples obtained from donors, grafts, preservation fluids and recipients.