Adult patients with chronic active EB virus infection (CAEBV) are few; however the disease runs an aggressive course. The goal of this study was to investigate the clinical characteristics, treatment as well as prognosis of CAEBV in adults. The clinical data of eight adult patients with CAEBV of were analyzed retrospectively. There were five male and three female patients with a median age of 47 (25-67) years old. The main clinical manifestations were fever, lymphadenopathy, splenomegaly, liver damage, abnormal coagulation and cytopenia. Peripheral blood EB virus DNA titers were significantly higher in all patients (4.14×104
copy/mL). Most patients received treatment with glucocorticoids, cyclosporine and chemotherapy containing etoposide (as recommended in the HLH-2004 program or the scheme of ECOP). One patient progressed to aggressive natural killer (NK) cell leukemia in 5 months after diagnosis. Another patient without fever or cytopenia is still living now, after receiving hormone therapy. The remaining 6 cases died with a median survival of 15 months. In conclusion, CAEBV in adults is a rare but serious disease, often with multiple system damage, from which the prognosis is very poor. Further research is necessary to improve the understanding of this disease.