The concentration of immunoglobulins G and M plus the electrophoretic profile of proteins was studied in the serum of 14 children with amebic liver abscess. There were different degrees of weight loss and of liver necrosis in all of them. The concentration of total proteins of the serum was subjected to different factors and resulted with wide individual variations. The same was obtained when the values of the fractions separated by electrophoresis were expressed in g/dl. On the other hand, percentual values gave a similar profile for all of the patients. Besides the significant increases of IgG. an inversion of the albumin/globulins ratio was found and an increase of the percentages of alpha-1, alpha-2 and gamma fractions. The importance that proteolytic anti-enzyme mechanisms may bear in the evolution of the lesion brought about in the liver by the enzymes liberated by the protozoa, is speculated.