Objective To evaluate the diagnostic significance and to analyze reasons of false negative cases forpreoperative ultrasonography， 99Tcm-sestamibi scintigraphy （MIBI scintigraphy）， and CT in primary hyperparathyroidism（PHPT）. Methods Clinical data of 69 patients with PHPT， who underwent operation in Affiliated Shengjing Hospital of China Medical University between Jan. 2003 and Aug. 2012 were retrospectively analyzed. Results There were 76 parathyroid lesions in 69 PHPT patients proved by operation and pathology， including 58 cases of parathyroid adenoma with 60 lesions， 7 cases of parathyroid hyperplasia with 11 lesions， and 4 cases of parathyroid carcinoma with 5 lesions. The sensitivity of ultrasonography， CT， and 99Tcm-MIBI scintigraphy were 81.94% （59/72）， 61.76% （21/34）， and 69.57% （16/23）， the accuracy of 3 kinds of tests were 78.67% （59/75）， 61.76% （21/34）， and 66.67% （16/24）， the positive predictive value were 95.16% （59/62）， 100% （21/21）， and 94.12% （16/17） respectively. There was significant differ-ence only between ultrasonography and CT in sensitivity （P=0.03）， no other significant difference was found （P＞0.05）.Conclusions Ultrasonography is complementary to 99Tcm-MIBI scintigraphy， but CT has little significance in diagnosis of PHPT. Both of ultrasonography and 99Tcm-MIBI scintigraphy should be used before operation routinely to localize parathyroid lesions.