Double-stranded DNA (dsDNA) viral infections constitute a major complication following solid organ and stem cell transplantation. Few therapeutic options are currently available for the treatment of such infections in highly immunocompromised hosts. Brincidofovir is an oral investigational drug with broad antiviral activity against dsDNA viruses in vitro, but clinical experience is limited. Here we report a young female who developed a mixed infection with adenovirus, cytomegalovirus, Epstein-Barr virus and BK polyomavirus after an allogeneic stem cell transplant, and was successfully treated with brincidofovir.