The European eel (Anguilla anguilla) is a catadromous fish with a complicated life cycle. The long-term impact of anthropopressure, environmental pollution and diseases have led to a risk of extinction. The aim of the present study was to determine the influence of Anguillid herpesvirus-1 infection on the innate immunity of European eel from natural conditions. Spleen phagocyte respiratory burst activity and potential killing activity, as well as pronephros lymphocyte proliferation stimulated by concanavalin A or lipopolysaccharide were measured. The analyses of the results showed that all studied parameters were significantly higher (P<0.05) in AngHV-1-negative fish compared to the ones where the presence of viral DNA was confirmed.