CASE PRESENTATION: A 53 nonsmoking HIV negative female from Nigeria in the U.S. for 2 years had two QFT-G read as negative with both mitogen values greater than 9 IU/ml. Both TB - nil values were less than 0.10 IU/ml. However, a PPD placed 2 weeks after the second QFT-G test was 15 x 20 mm and was considered positive. Therefore, she agreed to and was treated for latent TB. This was considered a false negative QFT-G test. A 65 nonsmoking HIV negative male from the Dominican Republic had two QFT-G tests read as positive. Both tests had mitogen values greater than 6 IU/ml. However, the nil values were greater than 2 IU/ml in each test, albeit TB - nil values were both greater than 1.8 IU/ml. The tests were read as positive but due to the high nil values a PPD test was placed. The PPD reading was 0 x 0 mm. Therefore, this test was considered a false positive and the patient was not treated for latent TB. Both patients had no symptoms and both chest roentgenograms were normal.