Two mortal cases of varicella pneumonitis are described. The patients were respectively 41 and 34 years-old men of good health. They caught the disease from their children. The disease lasted one week, and death was due in both cases to respiratory failure. The autopsy confirmed massive lung involvement with varicella pneumonia, and also showed other organs involvement (liver, spleen, pancreas, lymph nodes, oesophagus). In both cases, human fibroblast cultures infected by material obtained from cutaneous lesions (in the second case also from the spleen) revealed the presence of Herpesvirus varicellae. A review of 41 cases of adult mortal varicella in the literature demonstrates that death is practically always due to pneumonia and consequent respiratory failure. The dissemination of the virus in other organs is constant. Circumstances, such as pregnancy, immunosuppression, etc., which aggravate the prognosis of varicella in adults, are discussed.