Background: Toxocariasis was recorded as one of the most commonly zoonotic helminthic infections in the world and still a poorly diagnosed disease hence largely unknown either to health professionals and/or the general of Egyptian population. The excretory-secretory antigens of T. canis larvae (TES) are widely used for both the diagnosis and seroepidemiological studies. Aim of the work: The aim of the present study was to assess the relationship between toxocariasis and bronchial asthma in asthmatic children through means of a case-control study in Cairo, Egypt and to determine its relation to epidemiological risk factors, laboratory tests and clinical signs. Patients and Methods: The study included two groups (Group1): asthmatic group included 72 children with confirmed asthmatic bronchitis and (Group 2): non-asthmatic group included 72 children selected randomly as a control group. The sociodemographic data was assessed as risk factors for toxocariasis based on a questionnaire collected from the children's parents or guardians. The selected cases were subjected to stool analysis to exclude other parasitic infection, CBC for eosinophilia and immunoblot assay for detection of Toxocara canis IgG. Results: Out of 72 asthmatic patients toxocariasis IgG was positive in 16 cases (22.2%), negative in 56 cases (78.6%) compared to 5 positive cases (6.9%), and 67 negative cases (93.1%) in control group. There was a significant relation between positive antiToxocara IgG and asthmatic bronchitis. This study confirmed a significant correlation between the seroprevalence of Toxocara and possible socioepidemiological factors as contact with pets, geophagia and residence. Conclusion: Rising knowledge of toxocariasis will enable pediatricians to consider it as a cause of asthmatic bronchitis in their patients, initiate appropriate treatment, and educate patients and parents on how to avoid becoming infected