A method for a rapid and accurate demonstration of antibodies to Trypanosoma cruzi by using nitrocellulose paper strips coated with antigens of the parasite was developed and evaluated. Thirty-eight serum samples from 38 individuals infected with T. cruzi had a positive result in the test. Sera from normal individuals and individuals with antibodies to Toxoplasma gondii or Leishmania braziliensis had a negative result. The test was performed in a short period of time at room temperature. The antigen-coated paper may be kept for prolonged periods of time at 4°C or room temperature.