Primary hyperparathyroidism, most commonly due to a solitary parathyroid adenoma, has become an increasingly diagnosed condition and is one with great potential for cure following appropriate surgical intervention. Functional imaging with Tc-99m-based radiopharmaceuticals has contributed significantly to increased success in preoperative adenoma localization but the advent of fusion of this functional information with anatomical details obtained with computed tomographic imaging has yielded a potentially more powerful clinical tool and one that is particularly well suited to ectopic adenomas and cases of prior failed surgery. Aspects of this modality are discussed with reference to software- and hardware-based fusion techniques and evidence for efficacy. The allied technique of PET/computed tomography is also discussed.