Toxocariasis is a common helminthic infection that has a worldwide distribution. However, data from Lebanon about the prevalence of this infection are non-existent. We conducted a Toxocara seroprevalence study with 150 subjects attending the outpatient clinics at the American University of Beirut Medical Center between May and June 2004. Serum specimens were tested for anti-Toxocara antibodies by enzyme-linked immunosorbent assay and confirmed by Western blot. Multivariate analysis was performed to identify risk factors for infection. The seroprevalence rate of toxocariasis was 19%. Male gender and below high school education were significantly associated with a positive serological test (odds ratios = 3.1 and 2.8, respectively). Higher numbers of persons in the household, and low family income during childhood, were significant on bivariate analysis only. Toxocariasis is common in Lebanon. A large population-based survey is needed to confirm these results.