Purpose : To assess relative diagnostic value of Ga-67 planar, Ga-67 SPECT, and CT images for detection ofhead and neck tumors and cervical lymph node metastasis. Materials and Methods : Thirty eight patients ofpathologically proven head and neck tumors including squamous cell carcinomas(n=32), malignant lymphomas(n=3),undifferentiated carcinomas(n=2), adenocarcinomas(n=1) were enrolled in this study. Ga-67 planar and SPECT imageswere obtained with intravenous injection of 5mCi of Ga-67 citrate. On the basis of 30 and 20mm in the greatestdiameter of cervical lymph nodes, we compared lesion detectability of Ga-67 planar, SPECT, and CT. Results :Thirty eight cases of head and neck tumors were detected in 29 cases(76.3%) with Ga-67 planar image, 37cases(97.3%) with Ga-67 SPECT, and 32 cases(84.2%) with CT. 25 of 32 squamous cell carcinomas were positive withGa-67 planar image and all of 32 cases with Ga-67 SPECT. Both of two undifferentiated carcinomas were positivewith Ga-67 planar and SPECT images. Two of three malignant lymphomas were positive with Ga-67 planar image and allof three with Ga-67 SPECT. Eight of nine tumors were negative with Ga-67 planar image and those were less than30mm. One case of adenocarcinoma was negative with Ga-67 planar and SPECT images. Seven of nine lymph nodesgreater than 30mm were positive with Ga-67 planar image and all of nine with Ga-67 SPECT. On the basis of 20mm ingreatest diameter, 16 of 21 lymph nodes greater than 20mm were positive with Ga-67 planar and SPECT images.Conclusion : CT providing better resolution than Ga-67 scan permitted analysis of size and location of metastaticcervical nodes, however primary tumors of oral cavity, vocal cord, and nasopharynx were often not detected on CTwhen metallic and motion artifacts were present, where Ga-67 SPECT was useful. Ga-67 SPECT enabled betteranatomical localization than Ga-67 planar image and was useful in detection of lymph nodes greater than 30mm.