In La Réunion island (Indian Ocean) a seroepidemiological survey for toxocariasis was carried out among 387 subjects over 15 years old by Western blotting using Toxocara canis excretory-secretory larval antigens; 92.8% of the sera were positive. Statistical study, including logistic regression analysis, showed a significant correlation of Western blot results with sex, age, and absence of water supply. The final logistic model demonstrated that only the last 2 factors were significant multiplicative risk factors for toxocariasis. Sex was an independent risk factor. With this level of infection, we suggest that further surveys of ocular toxocariasis in children and teenagers of La Réunion would be advisable.