Increasing understanding of the epidemiology of post-transplant infections has led the development of preventative strategies that have reduced, though not eliminated, the risk of many serious infections after transplantation. At the same time, the rise of antimicrobial resistance has posed new challenges for the transplant recipient and clinician. This chapter discusses pre-transplant screening and treatment of pre-transplant infections; early post-transplant infectious complications including donor-transmitted infections; and a wide variety of bacterial, viral, and fungal pathogens that can affect the heart transplant recipient. Immunizations and strategies for safer living are discussed. The chapter will also highlight unique issues posed by the COVID-19 pandemic, including therapies, prophylaxis, and SARS-CoV-2 vaccine responses in heart transplant recipients. Effects of pathogens on allograft function and areas of active research are noted. The interested reader is encouraged to consult existing guidelines (see below) for further detailed recommendations.