Trypanosoma cruzi transplacental infection represents a serious public health concern in all the countries like Chile where recent success of insecticide spraying programs eliminated the vector. Because children infected with T. cruzi are usually asymptomatic, a study was designed including infected mothers and their children. The study was conducted for three years to establish diagnostic, treatment, and clinical observations variables. Mothers were tested for T. cruzi IgG, and the new born were examined for parasite DNA using PCR amplification. They were treated with nifurtimox and it was 100% effective, confirmed by successive PCR tests. It has been determined that there are 800 to 1000 new cases a year of transplacental Chagas' disease in Chile. This level of infection in the population should justify the establishment of a control and follow-up program for transplacental Chagas' disease.