The levels of albumin and immunoglobulins G, A, M were determined by using nephelometry technique in the cerebrospinal fluid and serum in 14 adults with tick borne meningoencephalitis at the beginning and after four weeks of disease. Intra blood-brain synthesis of IgG, IgA, IgM was evaluated by indexes of synthesis (Tibbling formula). The blood-brain integrity was estimated by CSF/serum albumin ratio. Increased albumin and immunoglobulins G, A, M levels were demonstrated in first examination and only elevated levels of albumin and immunoglobulin M lasted after four weeks. Albumin level in cerebrospinal fluid and albumin ratio were elevated in both examinations. The serum levels of albumin and immunoglobulins were similar in first and second examination. On the basis these results we conclude that in tested patients blood-brain integrity was disturbed still after four weeks of disease.