Compensatory renal hypertrophy is a process that has been known since Gustav Simon performed the first nephrectomy procedure in man in 1869. The present study reviews the literature and analyzes the factors relating to this process and its morphologic features. It has been reported that the degree of renal hypertrophy depends, among other factors, on the amount of nephrons lost as well as adaptative capacity of the surviving kidney when the pathologic kidney is removed. The present study also reports the changes in size of the surviving kidney observed at 6, 30, and 90 days after removal of the pathologic kidney in 40 patients. The results show a significant increase 6 days following nephrectomy and a significant decrease at 30 days to mean values higher than those of the preoperative evaluation. Ninety days after nephrectomy, these values significantly increase again but do not reach the same levels as those observed 6 days after nephrectomy. These findings are ascribed to the hemodynamic changes resulting from nephrectomy. These manifest immediately after the procedure and remain unchanged for days and subsequently the structural changes of renal hypertrophy prevail.