Adenoma is the leading pathologic entity in primary hyperparathyroidism (85%-90%). Although brown tumors are rarely seen, they may be the initial presentation and confused with tumors of the contiguous structures. Bilateral neck exploration by an experienced surgeon is the preferred approach. However, computed tomography, magnetic resonance imaging, ultrasonography, and isotope scanning can delineate most cases (75%-85%). We present a man with 2 adenomas. The second tumor was not recognized until the first one was removed. Combined imaging modalities and the measurement of intraoperative parathormone did not help in identifying the second adenoma. We review the common problems associated with diagnosis and treatment of multiple parathyroid adenomas.