Cerebrospinal fluid proteins of 14 patients with funicular myelosis were studied by paper electrophoresis. The serum proteins were also studied in 12 of these cases. The results were discussed regarding other data, as the length of disease, neurologic symptoms, hematologic changes, the absorption of radiocyanocobalamin. The CSF protein profile was mainly altered in the β globulin fraction, which attained pathologic levels in 6 cases. The serum protein profile revealed the intermediate fraction between β and γ globulins in 6 cases, as described by Furtado. Statistical analysis demonstrated the amount of the CSF β-globulin fraction to be proportional to the intensity of the central nervous system impairment. The correlation was not so well defined regarding to peripheral lesions. The amount of CSF β-globulin was found to be proportional to the intrinsic factor deficiency of the gastric juice, and to be inversely proportional to the index of radiocyanocobalamin absorption. Thus the increase in the CSF β-globulin fraction appears to be more apparent in cases of funicular myelosis in which the true Addison-Biermer disease is manifest.