In 2009, giant African pouched rats trained to detect tuberculosis (TB) evaluated sputum samples from 10,523 patients whose sputum had previously been evaluated by smear microscopy. Microscopists found 13.3% of the patients to be TB-positive. Simulated second-line screening by the rats revealed 620 new TB-positive patients, increasing the case detection rate by 44%. These data suggest that the rats may be useful for TB detection in developing countries, although further research is needed.