Background: Imaging studies, particularly simple and contrast-enhanced tomography, constitute the first diagnostic approach to detect recurrence of musculoskeletal tumors.The present retrospective study aimed to demonstrate the utility of scintigraphy plus SPECT/CT (single photon emission computed tomography) with thallium-201 ( 201 Tl) in the evaluation of malignant musculoskeletal tumors with suspicion of recurrence or metastatic disease.Methods: Eight weeks after the last therapy, scintigraphy and SPECT/CT studies were performed to assess regional recurrence and metastatic disease in 42 patients with different types of malignant musculoskeletal tumors, such as osteosarcoma, Ewing's sarcoma, rhabdomyosarcoma, retinoblastoma, synovial sarcoma, and Wilms tumor at the Hospital Infantil de México Federico Gómez.The positive predictive value (PPV) and the confidence interval of the scintigraphy and SPECT/CT were calculated when compared with the results of the histopathological analysis and the clinical and radiological follow-up for the identification of recurrence.Results: Scintigraphy was abnormal in 30 (71.4%) of the 42 patients; 33 lesions (30 patients) were detected by scintigraphy and lesions (21 patients) by chest X-ray and tomography of two regions.The SPECT/CT was performed on 30 patients, where lesions were detected in addition to the planar scintigraphy.Scintigraphy showed a PPV of 82%; SPECT/CT, 100%.Conclusion: 201 Tl-scintigraphy can be considered as an adequate study to identify the sites of tumor viability with a high degree of diagnostic certainty combined with the SPECT/CT technique.