In this article refined maximum and minimum interpediculate distances are published for use in diagnosis of intraspinal tumor and detection of spinal canal stenosis. The subject of spinal canal stenosis due to decrease of interpediculate distances is virtually unexplored. Availability of minimum norms should facilitate such studies.Concerning spinal canal stenosis due to diminished interpediculate distances, it is apparent that (a) there is such an anomaly, (b) it may, but need not be, associated with diminished mid-sagittal diameter of the spinal canal, and (c) it may be symptomatic. Illustrative cases are presented.