Aims & Objectives: Chickenpox is a common infection in childhood, caused by varicella zoster virus (VZV). Although generally considered as an innocent infection, the disease course can be complicated and even fatal, both in previously healthy as in immunocompromised children. By describing our ten-year experience, we aim to improve the knowledge about hospitalisations, complications, sequelae and mortality associated with VZV-infections. Methods We analysed retrospectively all hospitalization episodes involving patients with primary or secondary diagnosis of VZV-infection, using the hospital databases of the pediatric intensive care unit (PICU), general pediatric ward and pediatric hemato-oncology ward. All patients aged 1 month to 15 years and admitted from Jan 1st 2005 till Dec 31st 2014 were included. Results 89 patients aged 4 months to 12 years were included. 47/89 patients had relevant comorbidity, of which 30 were immunocompromised. The majority of patients (50/89) required admission to the PICU, mostly due to bacterial surinfection of soft tissues, septic shock, respiratory failure and epilepsia. 15/89 patients required invasive mechanical ventilation, 13/89 vasoactive mediaction, 2/89 ECMO. Of note, 32/50 patients admitted to the PICU had no relevant past medical history. Mortality rate was 4/89, of these 2 children were previously healthy. Bacterial surinfection with Streptococcus pyogenes (13/89) and Stafylococcus aureus (8/89) was often diagnosed. 36/89 patients suffered long-term sequelae. Conclusions Our data demonstrate the serious course of many VZV-infections in a tertiary pediatric centre. Also in previously healthy children, serious complications, high PICU referral rates, high occurrence of sequelae and significant mortality rates are noted.