Selective venous sampling (SVS) helps to interpret imaging results in patients with persistent primary hyperparathyroidism (pHPT). However, one of the drawbacks of conventional SVS may be low "spatial resolution", depending on the sample size. We modified SVS in the following way: first, patients underwent conventional SVS with up to 11 parathyroid hormone (PTH) samples taken. The quickPTH assay was used to measure PTH levels. The patients subsequently underwent super-selective venous sampling (super-SVS) in the region with the highest quickPTH level in the same session. The subjects were five consecutive patients with persistent pHPT investigated by various imaging techniques, none of which was considered conclusive. Therefore, all five patients underwent super-SVS, which was done successfully in four. Re-evaluation of the imaging results of these four patients resulted in localization of the parathyroid adenoma. Curative surgery was performed successfully in all four patients during the study period. Super-SVS increases the "spatial resolution" of conventional SVS and may have advantages when imaging results of patients with persistent pHPT are interpreted. Its true value must be analyzed in larger studies.