Surgical treatment for primary hyperparathyroidism (HPT) is effective in 90% of cases. Recurrent or persistent HPT occurs in 10% of cases. Parathyroid imaging is indicated to confirm and locate an abnormal gland before reoperation. The aim of this study was to evaluate whether the combination of 99Tcm sestamibi scintigraphy, MRI and venous blood sampling (VBS) improved the overall sensitivity for abnormal parathyroid gland detection. 18 patients with recurrent or persistent HPT underwent sestamibi scintigraphy (n = 18), MRI (T1 weighted and STIR sequences) (n = 18) and venous blood sampling (n = 12) at different sites (internal jugular veins, innominate veins, and superior vena cava). All patients underwent surgical exploration. MRI yielded positive results in 15 cases (sensitivity 88%), sestamibi scintigraphy in 14 cases (83%) and VBS in 10 cases out of 12 (83%). Combined results of MRI, sestamibi and VBS yielded positive results in 16 cases (94%). The combination of MRI, sestamibi scintigraphy and VBS improved accuracy in detecting abnormal parathyroid glands before reoperation.