The clinical outcome of the tick born infection Lyme borreliosis seems to be influenced by the type of immune response mounted during the disease, as suggested by various animal models. Here we report the serum and cerebrospinal fluid levels of tumour necrosis factor-alpha (TNF-alpha), transforming growth factor beta1 (TGF-beta1) and interleukin-6 (IL-6) in samples drawn at different disease intervals during the course of non-chronic neuroborreliosis (n=10), chronic neuroborreliosis (n=15), erythema migrans (n=8, serum only) and controls (n=7). When comparing early neuroborreliosis cerebrospinal fluid samples, significantly higher levels of TNF-alpha were found in non-chronic patients than in chronic patients (P<0.05). Moreover, TGF-beta1 was increased in the early serum samples of non-chronic patients, as compared to chronic patients (P<0.01). Elevated serum levels of TGF-beta1 were also found in erythema migrans as compared to neuroborreliosis and controls (P<0.05). The high TNF-alpha levels noted in early cerebrospinal fluid samples of non-chronic patients only, possibly reflects an ongoing pro-inflammatory immune response in the central nervous system, which could be beneficial in eliminating disease. High serum levels of TGF-beta1 probably mirror an anti-inflammatory response, which might play a role in controlling the systemic immune response.