The study is based on 371 cerebrospinal fluid (CSF) samples and 324 serum samples from 40 patients with neurocysticercosis (NC) submittted to treatment with praziquantel. The aim of the study is a critical evaluation on humoral immunity in CSF NC syndrome. The analysis of NC patients at diagnosis and in the follow-up period was performed considering three connected criteria: the clinical one, the CSF examination and the computed tomography. For the study of CSF and serum samples a systematization of collection was scheduled in relation to: diagnosis; period of treatment; follow-up. A total of 13 samples for each case for a follow-up period of two years was scheduled. For the study of humoral immunity a semiquantitative methodology was employed to verify the intra blood-brain barrier (BBB) gamma globulins synthesis. It was based upon electrophoretic profile data on CSF and serum proteins, and relations and indexes. Normal values were previously characterized in a normal control group. This group was formed by 50 patients with chronic headache who presented normal neurological examination, as well as, CSF examination and serum proteinogram under the safety limits of normality. To verify intra BBB gamma globulins synthesis it was considered the gamma globulin content of the CSF and serum, the gamma globulins/prealbumin + albumin relationship, the Link and Tibbling index, the intra BBB gamma globulins synthesis of Tourtellotte and col., and the appearence of oligoclonal bands in the CSF. Confirmation of the disease was performed by immunological reactions for cysticercosis: complement fixation test in CSF and serum; immunofluorescent test and enzyme-linked immunosorbent assay (ELISA) in CSF. Interference factors in the CSF NC syndrome were analysed at first such as those related to: clinical aspects, time of disease, previous dependence on corticotherapy, ventricular derivation shunts, tomographic findings. It was shown that all of them produce several degrees of interference in the intensity of the CSF NC syndrome. Data on intra BBB gamma globulins synthesis were verified in 37 patients (92.5%). It occured in a persistent pattern in 18 cases (45%) during all the study phases, and not snowed changes that might be related to treatment. On the other hand, it was shown that analysis of the results must always be performed case by case due to large dispersion of events observed and the differences of behavior of data related to humoral immunity, when critically analysed during diagnosis, treatment period and in the follow-up. Statistical studies confirmed the evidence of intra BBB gamma globulins synthesis and the safety of immunological reactions for cysticercosis when performed in CSF. Finally, enphasis is given for the alterations verified in the CSF examination wich has been, is and shall continue to be basic for neurocysticercosis studies.