<b>1979</b> <h3><b>Objectives</b></h3> Skeletal tuberculosis can mimic malignant lesion with its destruction of bones and increased FDG uptake on PET imaging. This study aimed to investigate the feature of such kind lesion in PET/CT imaging, hoping to improve the diagnostic accuracy. <h3><b>Methods</b></h3> From Jan 2009 till Sep 2012, 87 patients with FDG-avid bone lesion(s) caused by unknown reason were included in the study. All patients undertook the FDG PET/CT scan 60min after the injection of about 10mCi 18F-FDG. <h3><b>Results</b></h3> Among all 87 patients, 19 patients were confirmed of skeletal tuberculosis by pathology or by following anti-tuberculosis treatment. The mean SUVmax was 8.3 (4.4~15.9); 12 patients had clinical symptoms (low fever, night sweat, etc.); 15 were multi-lesions (78.9%), including multiple involvement in lymph nodes or organs; 4 were single lesion (21.1%). All patients had vertebrae involvement, 12 located in lumbar vertebrae. 6 patients (31.6%) had a confirmed history of pulmonary tuberculosis; Calcifications in lungs or hilar lymph nodes were seen in 8 patients on CT images (42.1%). <h3><b>Conclusions</b></h3> For patients with FDG-avid bone lesions by unknown causes, skeletal tuberculosis should be considered. Though the diagnostic specificity of PET/CT in skeletal tuberculosis is not satisfying, it can be used to locate the site of biopsy. The clinical symptoms (low fever, night sweat, etc.), previous history of tuberculosis and calcification findings on CT images may help to improve the accuracy of diagnosis.