Helicopter Emergency Medical Services are complementary services to the emergency medical service of developed countries that allow to give medical assistance to remote areas and assist patients who are in a critical situation to be transferred to the hospital as soon as possible providing them with medicalised care on board. This thesis will explain the existing services in Catalonia that have helicopters for the transport of critically ill patient. Subsequently, the existing services in Catalonia will be compared with other services of a different geographic and population scope than the Catalan services, to establish a comparison and understand how to plan this type of service. In addition, the fleet of aircraft that each medical service needs to be able to make the transfer and take the patient to the hospital will also be analysed. Therefore, each medical emergency considers the best type of helicopter that suits its need considering the type of region in which it operates, the population that lives there and the type of operation that it will perform. All these will be explained below, analysing the helicopters belonging to each of those services, the technical characteristics of each of them, the missions that each helicopter can perform, the configurations of each helicopter and a comparison will be made between all the helicopters belonging to the services. Finally, the heliports where this type of service operates will be analysed, as to transport the patient to the hospital, this hospital needs to have a heliport at the top or next to the building. Therefore, it also explains the characteristics that heliports must have, depending on whether they are located on the surface or elevated, the types of heliports that exist and then the analysis of the proposals for the different types of services for improve the network of rescue heliports.