BackgroundToxocariasis is a zoonotic disease that poses a threat to public health worldwide. This disease primarily affects children and is caused by the presence in the digestive tract of a common roundworm of dogs, Toxocara canis, or cats, Toxocara cati. Toxocara is responsible for the presentation of various syndromes in humans depending on the affected organs.MethodsIn this study, the prevalence of anti-T. canis antibodies was investigated in children aged 3–16 years from semirural populations in the municipalities of Amecameca and Chalco in México. An ELISA was used to determine the presence of anti-T. canis antibodies in blood samples.ResultsOf the 183 sera obtained for this study, 22 were positive for anti-T. canis antibodies (12.02 %). Of these, 6.50 % were from males and 5.4 % were from females. Risk factors were investigated and it was found that living near a cattle operation had a statistically significant association with (Chi2 = 5.51 and p = 0.01) and was a risk factor for (OR = 4.25, p = 0.02) seropositivity to T. canis. Keeping dogs with short hair (Chi2 = 3.24 and p = 0.07) showed a tendency toward seropositivity for T. canis, as did the habit of sleeping with pets (Chi2 = 3.46 and p = 0.06).ConclusionsSeropositivity to T. canis was confirmed in children in the Amecameca and Chalco regions of México and the risk factors were identified. These findings provide important insight into the prevalence and spread of this zoonotic parasite.