Hemophagocytic lymphopcytosis (HLH) is a life-threatening condition. It can occur either as primary form with genetic defects or secondary to other conditions, such as hematological or autoimmune diseases. Certain triggering factors can predispose individuals to the development of HLH. We report the case of a 25-year-old male patient who was diagnosed with HLH in the context of adult-onset Still's disease (AOSD) during a primary infection with Epstein-Barr virus (EBV). During therapy with anakinra and dexamethasone, he was still symptomatic with high-spiking fevers, arthralgia, and sore throat. His laboratory values showed high levels of ferritin and C-reactive protein. His condition improved after the addition of rituximab and cyclosporine to his immunosuppressive regimen with prednisolone and anakinra. This combination therapy led to a sustained clinical and serological remission of his condition. While rituximab has been used successfully for HLH in the context of EBV-associated lymphoma, its use in autoimmune diseases is uncommon. We hypothesize that the development of HLH was triggered by a primary EBV infection and that rituximab led to elimination of EBV-infected B-cells, while cyclosporine ameliorated the cytokine excess. We therefore propose that this combination immunosuppressive therapy might be successfully used in HLH occurring in the context of autoimmune diseases.