Varicella is a very common childhood disease responsible for an important number of hospitalizations every year in Spain. The aim of this study was to assess the burden of chickenpox hospitalizations in Spain in the 7-year period between 1999 and 2005. Data of hospital discharges relating to varicella were obtained from the Conjunto Mínimo Básico de Datos (CMBD), the Spanish surveillance system for hospital data. All paediatric hospitalizations for primary varicella that occurred between 1 January 1999 and 31 December 2005 were selected. The hospitalization rate for the 7-year study period was 23.06 hospitalizations/100 000 population. The highest incidences of hospitalizations were observed in the youngest groups (60.79 and 55.65/100 000 population for ages 0-12 months and 1-2 years respectively). Nineteen deaths were reported during the study period. The median length of stay in hospital was 4 days (interquartile range 3-7 days). Despite the availability of effective varicella vaccines, chickenpox remains an important cause of hospitalizations in Spain.