A rapid diagnostic test (RDT) is a test that can quickly determine (from minutes up to 2 h) a diagnosis. It is a simple, quick, and inexpensive technique that does not require complex equipment or specialized staff. For this reason, such tests have been proposed for the diagnosis of Chagas Disease (CD), which affects populations difficult to reach, or migrants in nonendemic areas, where there is a low prevalence of the disease. With these notes we take into consideration one of the best RDTs for CD currently available on the market as an example and make some comments on its use in the field on the base of the current evidences.