Background. Recurrent laryngeal nerve (RLN) injury is a rare complication for patients undergoing neck exploration for primary hyperparathyroidism (pHPT). Distances between RLNs and parathyroid adenomas have not been previously published. In this study we used a RLN monitor to identify the RLN and to measure the proximity to parathyroid tumors. Methods. Patients with pHPT (n = 136) underwent neck exploration and had the clinical data recorded prospectively. Adenomas were recorded in 1 of 4 locations (right upper, right lower, left upper, left lower). Measurement of RLN to adenoma distances were recorded intraoperatively with the gland in situ. The RLN location was confirmed with a RLN monitor. Results. The average RLN to adenoma distance was 0.52 ± 0.52 cm. Adenomas in the right upper position were significantly closer to the nerve (0.25 ± 0.39 cm) compared with adenomas in the left upper (0.48 ± 0.61 cm, p = .03), left lower (0.70 ± 0.53 cm, p<.001), and right lower position (1.02 ± 0.56 cm, p<.001). Left upper adenomas were also significantly closer to the nerve compared with right lower adenomas (p<.001). Adenomas in the right upper position abutted the nerve more often (47 %) compared with adenomas in other positions (p = .001). There were no perioperative characteristics that predicted tumor abutment. There were no permanent RLN injuries. Conclusion. In patients with sporadic pHPT, parathyroid adenomas in the right upper location have, on average, greater proximity to the RLN and are more often directly abutting compared with adenomas in other locations.