PARTIAL nephrectomy, the removal of a portion of the renal parenchyma, is a conservative renal surgical procedure which has not been used with the frequency it deserves. It provides a means of complete eradication of disease in an isolated portion of the kidney and is not fraught with the dangers that have been attributed to it provided certain fundamental principles are used and executed. In many instances it is by far the most conservative approach and the results can be extremely gratifying. There is a difference of opinion as to the definition of partial versus heminephrectomy, but we agree with Culp and Hendricks1 in that for practical purposes the term partial nephrectomy means a removal of a part of the renal parenchyma, regardless of the amount of tissue removed. In an attempt to evaluate the procedure, we have reviewed our experience from 1952 to 1965. Thirty-five cases constitute the