The purpose of this study was to evaluate the usefulness of technetium-99m tetrofosmin (Tc-99m TF) single photon emission computed tomography (SPECT) in the detection of cervical lymph node (LN) metastasis in nasopharyngeal carcinomas (NPC), and to compare Tc-99m TF SPECT results with computed tomography (CT) findings. Fifty patients with biopsy-proven NPC and suspected cervical LN metastases underwent head and neck Tc-99m TF SPECT and CT to detect cervical LN metastases. Cervical LN metastases of 40 patients were confirmed by histopathological examination of biopsy samples. For 22 LN lesions with discordant results between Tc-99m TF SPECT and CT, Tc-99m TF SPECT could correctly detect 4 metastatic and 7 benign LN lesions while CT could correctly detect 5 metastatic and 6 benign LN lesions. Agreement positive results of Tc-99m TF SPECT and CT could correctly detect all of the 18 metastatic LN lesions. Tc-99m TF SPECT has a better specificity but a lower sensitivity for detecting cervical LN metastases in NPC when compared with CT. The combined use of Tc-99m TF SPECT and CT could significantly increase the accuracy of detect cervical LN metastases in NPC compared with the single use of either Tc-99m TF SPECT or CT.