The purpose of this article is to summarize existing literature about healthcare-associated infection (HAI) in the medical transport environment and to define the term medical transport-associated infection (MTAI) to unify all previous work under a single umbrella with the objective of providing a standardized definition for future research. A review of the literature yielded 34 relevant articles. These studies show that there are pathogens in the ambulance environment, that emergency medical services (EMS) personnel do not regularly comply with hygiene practices, and that patients are potentially affected by HAI as a direct result of ambulance exposure. Prospective studies must be conducted to truly understand the impact that ambulance exposure has on HAIs. MTAI is a subset of HAI and is defined as any infection acquired as a direct effect of exposure in a medical transport setting.