The transport of critically ill patients is a complex process, made up by several phases involving the healthcare professionals. It requires a careful planning for the prevention of potential complications undermining the patients' safety outside critical care environment. Literature review about complications and adverse events reported during intra and inter-hospital transport of critically ill adult patients. Intra-hospital transfers are affected by adverse events rates ranging from 22.2 to 75.7% in the published literature. Major adverse events, defined as life threatening conditions that require urgent therapeutic intervention, vary from 4.2 to 31%. Death is a rare occurrence. Adverse events during interhospital have a maximum rate of 34%. Technical incidents represent a typical feature of these transports. Authors reported problems to gas supply, ambulance electric system, equipment. There is a lack of studies about the complications related to rotary wing inter-hospital transports. While extracorporeal membrane oxygenation/extracorporeal life support patients seem to be the most complex category of critically ill to be transported outside the hospital, 11 papers revealed only 29 adverse events ranging from 0 to 17%. No deaths were recorded. Currently, research must explore more accurately how much transports affect the outcome of patients, and what are the most appropriate time-frames to assess the consequences of transfers on patients' clinical conditions.