Varicella (chickenpox) is one of the most frequent highly infectious diseases in childhood. It is caused by varicella-zoster virus. Lethal complications are rare. Focused on histological findings, we present a case of a sudden unexpected death of an otherwise healthy 18-month-old girl due to varicella-induced pneumonia. The histological and immunohistochemical investigations of the lung tissue revealed typical findings of a varicella pneumonia: haemorrhagic and necrotic nodules, intra-alveolar fibrin, numerous neutrophilic granulocytes, lymphocytes, plasmacells, macrophages, multinucleated giant cells and hyaline membranes. Varicella-related deaths are preventable by vaccine. To prevent complications and lethal outcome of varicella as reported here, the recommendations concerning vaccination against varicella must be taken into account in paediatric practice.