After a brief review on various attempts to control intestinal helminthic infections in different regions, the author presents the results obtained with repeated mass treatment for ascariasis and hookworm injection in two farms in the municipality of Sumidouro, State of Rio de Janeiro, and in an orphanage in the State of Guanabara. Mass treatment proved no to be the most important tool for controling helmínthic infections, although good results were obtained during treatments; howewer the previlence of the infeciton retumed to leveis near the primitive when treatments were interrupted. Sanitation and general measures regarding social and economic improvement are desirable for better and permanent results.