The pathology and clinical follow-up of 26 patients with Huerthle cell adenomas and 3 patients harboring Huerthle cell carcinomas, who were treated from 1950-1979 were reviewed. Although benign lesions could not be distinguished from malignant tumors by cytologic features alone, other pathologic features allowed differentiation. A total thyroidectomy was performed in only 1 patient; the remaining patients were treated by less extensive operations. None of the patients with benign adenomas, including those with tumors greater than 2 cm in diameter, experienced recurrent or metastatic disease. The period of observation varied from 2-22 yr (mean, 8.5 .+-. 7.7 yr). Lobectomy evidently is a satisfactory operation for removal of benign Huerthle cell tumors. Total or near-total thyroidectomy should be reserved for cases displaying pathologic evidence of malignancy.