OBJECTIVE The aim of the present study was to compare the surgical results with contrast-enhanced [99mTc]methoxyisobutylisonitrile ([99mTc]MIBI) single-photon emission computed tomography (SPECT)/computed tomography (CT) results by adding the simultaneous single phase contrast to the [99mTc]MIBI SPECT/CT examination. METHODS Between November 2016 and January 2018, 24 (21 female, 3 male) patients who underwent an operation after preoperative contrast-enhanced [99mTc]MIBI SPECT/CT, and 49 asymptomatic patients (42 female, 7 male), who did not undergo surgery, were included in the study. RESULTS Sensitivity and specificity rates of contrast enhanced [99mTc]MIBI SPECT/CT were 100% and 100% when evaluated together with surgical results. The rate of detection in asymptomatic patients was found to be 93.8%. CONCLUSIONS With the contrast-enhanced [99mTc]MIBI SPECT/CT imaging, both high sensitivity and specificity values were achieved in the preoperative localization of parathyroid adenomas (PTAs) and high detection rates were obtained in the asymptomatic group. The use of contrast IV during the [99mTc]MIBI SPECT/CT in patients without contraindications increased both preoperative localization rates of adenomas and detection rates of asymptomatic hyperparathyroidism cases. BACKGROUND Parathyroid adenoma, Primary Hyperparathyroidism, [99mTc]MIBI, SPECT/CT.