Environment is the main source of infections for humans. Annually, the accumulation of a lot of an invasive material occurs in it. As a rule, almost all of both wild and domestic animals are infested with helminthes. Toxocarosis is a dangerous disease. The invasion by Toxocara is eurycoenose among both animals and humans. Toxocara eggs are very stable to the impact of adverse factors of surroundings. They can be preserved in soil for a long time and are able to withstand action of diverse chemical agents. As for the eggs dissemination of Toxocara as well as of other helminthes, among other creatures, cockroaches and flies can act as a mechanical vector (according to some reports, also earthworms can). This investigation is dedicated to an experimental introduction of Toxocara larvae infection to earthworms Eisenia Fetida. There was conducted an infestation of the earthworms Eisenia Fetida via soil seeded by invasive eggs of Toxocara. Migration and expansion of the Toxocara larvae were found in tissues of earthworms.