AbstractIn a series of 948 patients operated on for primary hyperparathyroidism (HPT) by one surgeon (JNA) from 1952 to 1992, there were 242 (26%) instances of coincidental thyroid and parathyroid disease. Of these, 211 had benign thyroid lesions. In the remaining 31 cases HPT was associated with nonmedullary thyroid carcinoma; all were treated by resection of parathyroid adenomas and thyroidectomy. One patient died of unrelated cause (carcinoma of breast) 11 years following surgery. The remaining 30 patients are living and well 2 to 20 (mean 8.2 years) years after surgery; there was no recurrence or thyroid cancerrelated mortality in the series. In contrast to prior reports, only six (20%) of our patients had a history of prior radiotherapy. We suggest that during neck exploration for HPT, the entire thyroid gland be evaluated and all palpable nodules resected and submitted to pathologic study.