To evaluate the measure against tuberculous infection using QuantiFERON^® TB-Gold In-Tube (QFT-3G), we retrospectively analyzed 77 health-care workers (HCWs) in our hospital who had been examined by QFT-3G several times from June 2010 to November 2011. Fifteen cases had positive QFT-3G results at least once. However, 3 of 15 cases had false positive results. Therefore caution is advised when evaluating QFT-3G results. No difference was noted in QFT-3G-positive rates by age or gender. In analyses according to occupation, the QFT-3G-positive rates were highest for radiology technicians (2/7: 28.6%), and higher in order of laboratory technicians (2/8: 25%), nurses (4/34: 11.8%), and doctors (1/15: 6.7%). QFT-3G-positive rates were also high among nutritionists and physiotherapists in the tuberculosis ward. Therefore it is necessary to strengthen the prevention of tuberculous infections not only for doctors and nurses, but for radiology technicians and the other professions working in the tuberculosis ward.