About six observations of toxocariasis (visceral larva migrans syndrome). We relate six observations of toxocariasis among children. In one case, an ocular localization is probable. For other five patients, they are inapparent forms. The allergologist pediatrician may be consulted because of a major hypereosinophilia (greater than 10,000/mm3) and an elevation of total IgE (greater than 2,000 UI/ml). Allergic and current parasitologic assays are negative and diagnostic key is given by toxocara serology. We insist on interest and reliability of passive hemagglutination test with a purified antigen (titer greater than or equal to 1/320). Treatment now is preferably flubendazole (50 mg/kg/day for six days) eventually renewed.