There is scanty information about invasive aspergillosis (IA) in the pediatric population. A review of IA at Hospital Infantil Universitario Niño Jesús between 1996 and 2006 was undertaken to analyze incidence, risk factors, and treatment response. Twenty patients were diagnosed with probable or proven IA during the study period, with a cumulative incidence of 1.96%. Incidence was higher in hematopoietic stem cell transplantation (HSCT) recipients: 2.26% (3.5% in allogeneic HSCT and 1.2% in autologous HSCT). A significative increase in IA incidence was observed along the study period (P=0.013), although this increase did not reach signification if only proven cases were compared (P=0.058). Most patients presented multiple risk factors for IA (87% more than 1, and 47% more than 3). The most frequently described risk factor was chemotherapy (90%), after by long-term neutropenia (90%), and corticotherapy (75%). Main locations of the infection were pulmonary (8 patients), cutaneous (3 patients) and intestinal (3 patients). Six patients presented disseminated IA. Initial response to treatment was 55%, although 3 of these cases had a subsequent episode. Global antifungal response, at the end of the follow-up, was 45%. IA-related mortality was 55%. Global mortality was 90%. Only 2 patients (isolated cutaneous IA cases) survived. Seven patients died due to their underlying malignant disease without active fungal disease. Incidence of IA in oncology children is increasing, and in adults. In our experience, IA is a marker of poor outcome even for patients who initially respond to antifungal treatment.