The shoulder girdle presents unique features for the preoperative planning of musculoskeletal tumors. This is the first trial to evaluate positron emission tomography (PET) analysis for preoperative planning in shoulder girdle tumors. Fifty-two patients were examined with fluorine 18 fluoro-2-deoxy-D-glucose (FDG)-PET and/or alpha-methyltyrosine (FMT)-PET. Imaging findings were visually inspected in conjunction with computed tomography and/or magnetic resonance imaging, and standardized uptake values (SUVs) were generated. FDG-PET may be useful for the detection of malignant tumors and screening for metastatic spread, with the qualitative assessment of heterogeneous biologic activity providing a correct approach for biopsy. The mean SUVs for malignant tumors were significantly higher than those for benign lesions. However, a useful cutoff SUV was not found in either FDG- or FMT-PET for differentiating malignant from benign tumors from receiver operating characteristic curve analysis. SUVs on FDG- and FMT-PET may merely be limited to differentiating malignant from benign tumors in the shoulder girdle.