Cerebrospinal fluid (CSF) and serum samples of 10 patients with neurocysticercosis under treatment by praziquantel were studied in four occasions: before treatment (day 0) and during treatment on three ocasions (days 1, 7 and 21). The immunological reaction analyzed were: ELISA-G and ELISA-M; immunofluorescence-G and immunofluorescence-M; complement fixation. The changes and the variability of results observed through these reactions in this study bring new data that confirm neuroimmunological findings already described in the disease. Acute phase response was found in CSF in 6 cases and only in one case in serum by ELISA-M and immunofluorescence-M. ELISA-G in CSF and serum showed a better sensitivity than the other reactions for diagnosis and for follow-up. Emphasis is given to the importance of the simultaneous realization of several immunological reactions in CSF and serum in patients with neurocysticercosis.