Despite the specialist activity of Infectious Diseases not being officially recognised, the majority of the hospitals in the autonomous communities of Spain are equipped with structures, with significant heterogeneity among them, to be able to offer high quality care in these diseases. The main characteristics of and Infectious Diseases Department is its important healthcare activity, more than in other officially recognised medical specialities, and also its important interrelationship with other services in the hospital which is clearly horizontal healthcare. Furthermore, the aforementioned infectious disease care units have developed important activities in the arena of community and public health and, in collaboration with health authorities, contribute to the rational use of antimicrobials and the relationship with Primary Care. The future of specialists in infectious diseases, when they are officially recognised, will be the creation of clinical management units in every health institution with the objective of coordinating all the specialised health care, both in the hospital environment and in its health area of influence.