Healthcare-associated infections are not only an important public health problem but also have a relevant socioeconomic impact. The overall estimated yearly costs vary between 3.5 billion euros in the United States to 1.3 billion euros in England. In Italy estimated costs are 2.5-5.0 billion euros/year with the cost of a single case ranging from 9,000 to 10,500 euros. The present study aimed to describe the type and distribution of hospital costs for healthcare-associated infections, the economic impact of prevention programs and models for cost effectiveness evaluation of prevention programs. A review of the existing published literature was conducted; studies were included in the review according to whether they had included a control group and to the number of subjects enrolled. Healthcare associated infections lead to increased direct, indirect and intangible costs. Most economic analyses that have been performed consider only direct costs, estimated by calculating the costs of extra days of admission. Surgical site and bloodstream infections were found to be the most costly types of infections, followed by lower respiratory tract and urinary tract infections. There was wide variation in costs between individual hospital departments and countries. Control and prevention strategies have been shown to be effective and efficient but should be evaluated within a specific local context. Prevention programs should therefore take into consideration the local situation.