Routine thyroid suppression with administration of exogenous thyroid hormone has altered management of thyroid nodules. During 22 years the mean number of thyroid operations per year in our hospital declined from 68.3 to 18.5, while the proportion of cancer cases in those operated on rose from 4% to 36.5%. The operative mortality in 1,009 thyroidectomies was zero. In the last ten years, 54 patients have had surgical removal of thyroid cancer. Only two of these have died of tumor. That a decrease in size of malignant thyroid nodules was recorded in four patients on suppression is evidence that this technique does not prevent progression of thyroid cancer. Thyroid suppression is beneficial in selection of patients for operation. If this approach is to be used routinely however, strict adherence to absolute and relative criteria for surgery must be employed by both internist and surgeon.