We present a patient with elevation of total serum IgE, eosinophilia and Toxocara exoantigen specific IgG and IgE antibodies (detected by ELISA and RAST, respectively). We ruled out atopy and other parasitic diseases common in our habitat (e.g., Echinococcus granulosus, Ascaris lumbricoides, Schistosoma mansoni). The patient was asymptomatic over the four years of the study, and the levels of total serum IgE, eosinophils and Toxocara exoantigen specific IgG and IgE remained high. Although at present, immunodiagnostic tests have a high sensitivity and specificity for toxocariasis, their value is limited. This is illustrated by the fact that in our patient these techniques could not distinguish between past and present infection.