This multicenter, prospective, observational study assessed the global economic impact of HIV care in a large cohort of HIV-infected children and adolescents in Italy. Three pediatric departments of reference participated on a voluntary basis. Centers were asked to enroll all their children during the period April 2010-March 2011. At enrollment, a pediatrician completed a questionnaire for each patient, including the type of service at access (outpatient consultation or day hospital), laboratory tests, instrumental examinations, specialists' consultations, antiretroviral therapy and opportunistic illness prophylaxis. Eligible patients had a confirmed diagnosis of HIV infection caused by direct vertical maternal-fetal transmission, their age ranging from 0 to 24 years. Since patients routinely have quarterly check-ups in all three centers, we adopted a three-month time horizon. Health-care services were priced using outpatient and inpatient tariffs. Drug costs were calculated by multiplying the daily dose by the public price for each active ingredient. A total of 142 patients were enrolled. More than half the patients were female and the mean age was 14 years, with no significant differences by center. There were substantial differences in health-care management among the three centers, particularly as regards the type of access. One center enrolled the majority of its patients in day-hospital and prescribed a large number of clinical tests, while children accessed another center almost exclusively through outpatient consultation. Drug therapy was the main cost component and was very similar in all three centers. The day-hospital was the second highest cost component, much higher than outpatient consultation (including examinations), leading to significant differences between total costs per center. These findings suggest that a recommendation to the Italian National Health Service would be to use more outpatient consultation for patients' access in order to increase their efficiency in treating pediatric HIV infection.