The aims of this chapter are: 1) to present a review of theories on service innovations, and how they could be focused on hospitals; 2) to present a methodology based on these theories in order to identify and to understand hospital innovations. This is done through interviews based on a questionnaire to detect services innovations, which are generated and adopted by hospitals; 3) to understand the role of national public health institutions and the actors involved in the service innovations in three hospitals in Mexico. The results show that there are four sources of innovations: a) Those external policies or guidelines that come from public health or federal or state regulatory institutions; b) the internal hospital initiatives of medical personnel, administrators and workers; c) the hospital’s suppliers; and d) the hospital’s patients, who, in the case of Mexico, scarcely participate in innovations, while they quite commonly do so abroad. Hospitals’ innovativeness is correlated with the phase reached, beginning with knowledge and continuing with persuasion, decision, implementation and confirmation. The main contribution to innovations in the hospitals studied comes from the medical services. A recommendation is the involvement of the clients to improve and participate in the hospitals’ innovations.