Toxocariasis is an infection with a larva of dog or cat ascaris (Toxocara canis, T. cati), which, unable to turn into fully matured form, circulates in the system and reaches various human organs and tissues. Risk factors of Toxocara canis/cati infection consist of age 3-10 years old, male sex, living in the country, possession of dogs, especially puppies and young dogs up to 3 years old and pica (eating inedible things) and onychophagia (biting one’s nails). Among clinical forms of toxocariasis usually characterized are visceral larva migrans syndrome, ocular migrans syndrome and covert. In this paper, a case of a 3-yearold boy from a rural environment, admitted because of suspicion of eosinophilic leukemia is presented. In the boy with a high eosinophilia of peripheral blood, after excluding the initial diagnosis and numerous parasitic diseases, a generalized form of visceral larva migrans syndrome was recognized. Due to multiple recurrence of symptoms in the boy and repeating hospitalisations on account of that a more detailed family interview was taken, from which it followed that the boy eats a lot of contaminated, by the present there puppies, sand, from the garden adjacent to the house. The observed by the parents pica, meaning eating inedible things, in this case sand, and presence in the vicinity of the house of neglected, not disinfestated puppies was the cause of severe form of infection in the child and of recurrence of symptoms. Considering the persistence of Toxocara canis infection in dogs in Poland and of the possibility of becoming infected with toxocariasis, prophylactic actions are essential, e.g. properly managed dog disinfestation, especially puppies. It is also important to change the sand in sandpits often, limit the number of homeless animals, take dogs for walks away from places where children play etc., but also to shape proper hygienic behaviour in children. An opportunity to resolve this epidemiological issue is a targeted cooperation of medical, veterinary, sanitary and public services.