Toxocariasis is a zoonosis due to infection of humans by dog or cat roundworm (Toxocara canis, T. cati). Humans become infected by ingestion of infective eggs either from soil, dirty hands, raw fruits and vegetables or larvae from undercooked meat of paratenic hosts. The aim of the study was to evaluate the level of contamination of soil samples from households of children with diagnosed toxocariasis in rural and urban areas of Łódź voivodeship. In the years 2004-2007 toxocariasis was confirmed in 178 patients of the Polish Memorial Hospital in Łódź. The soil samples were collected from 53 courtyards of patients' domiciles. Toxocara spp. eggs were isolated from the samples using flotation technique (Dada 1979). The examinations revealed the high prevalence of ground contamination with Toxocara eggs in both, rural (30.4%) and urban areas (23.3%). The presence of Toxocara eggs in households enlarges the risk of re-infection for children with diagnosed toxocariasis, especially in rural areas where the high level of contamination was detected.