Abstract: Objective To explore the clinical value of ⁹⁹Tc^m-tetrofosmin(⁹⁹Tc^m-TF)in the diagnosing of lung neoplasms. Methods ⁹⁹Tc^m-TF lung affinity tumor imaging data from 41 patients in our department were retrospectively reviewed. Chest computer tomography(CT) and ⁹⁹Tc^m-TF SPECT lung affinity tumor imaging were performed within one week before treatment. Diagnostic efficiency of the two methods in identifying lung neoplasm characteristics were evaluated by comparing final diagnosis results. Cases were grouped into tumor sizes, as follows: not less than 3 cm and less than 3 cm with a 3 cm threshold. The diagnostic efficiencies of ⁹⁹Tc^m-TF SPECT imaging of the two groups were compared. Results The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of ⁹⁹Tc^m-TF imaging in diagnosing lung neoplasm were 66.7%, 35.7%, 56.1%, 66.7% and 35.7%, respectively, whereas the corresponding values for chest CT scanning were 92.6%, 50.0%, 78.0%, 78.1% and 77.8%. Thus, CT was more sensitive(χ²=5.594, P < 0.05) and accurate(χ²=4.473, P < 0.05) than ⁹⁹Tc^m-TF SPECT imaging, but was not specific(χ²=0.583, P > 0.05). The sensitivity, specificity, and accuracy of ⁹⁹Tc^m-TF imaging for the group with a size of not less than 3 cm were 78.9%, 25.0%, and 69.6%, whereas the corresponding values for the group with less than 3 cm size were 37.5%, 40.0%, and 38.9%, respectively. No significant difference was found in specificity(χ²=0.28, P > 0.05) between the two groups, but specificity(χ²=4.352, P < 0.05) and accuracy(χ²=3.858, P < 0.05) were significantly different between the groups. Conclusions CT was superior in diagnosing lung cancer compared with ⁹⁹Tc^m-TF. The value of ⁹⁹Tc^m-TF may be improved when clinical doctors screen the proper patients.