A three years follow-up of the level of serum total IgE was made for the first time in three patients with strongyloidiasis after efficient treatment. The decrease of IgE was slow and progressive, showing a logarithmic curve. This regular decrease of total serum IgE could be used as an additional criterion for the evaluation of the efficiency of drug therapy in patients with strongyloidiasis. The persistence of high levels of total IgE two or three years after the elimination of the intestinal parasites, after the return of blood eosinophils to a normal level (within six months), and after the disappearance of specific antibodies, shows that the regulation of the IgE elimination seems to be a complex mechanism.