We evaluated the efficacy of technetium-sestamibi ((99m) Tc-MIBI) SPECT/CT for planning parathyroidectomy in cases with primary hyperparathyroidism (pHPT), comparing with planar scintigraphy and ultrasound (US), in an aim to establish the proper surgical strategy according to the preoperative imaging studies. A retrospective review of consecutive 75 pHPT patients who had been operated on was conducted. The results of preoperative imaging modalities and the operative finding were analyzed. Seven cases were found to have multiple hyperplastic glands, and no responsible gland was found in three cases. Four cases underwent only US scan for preoperative imaging. Remaining 61 cases were found to have single adenoma, and were included in the evaluation of localization imaging. US scan, (99m) Tc-MIBI planar scan and (99m) Tc-MIBI SPECT/CT showed accurate localization in 77.0% (47/61), 75.4% (46/61) and 88.5% (46/52) of the evaluable cases, respectively. US and (99m) Tc-MIBI planar scan demonstrated consistent result in 42 cases (68.9%), and those cases showed accurate localization in 90.5% (38/42). When both US and (99m) Tc-MIBI SPECT/CT was consistent, all 37 lesions had been correctly indicated. No clinico-pathological features were suggested to influence in demonstrating the localization, other than only (99m) Tc-MIBI SPECT/CT exhibited 100% sensitivity in ectopic glands. Combination of US and (99m) Tc-MIBI SPECT/CT certainly contributes to the planning of minimally invasive operation in cases with pHPT by indicating correct localization of single adenoma.