The thesis entitled: The clinical validity of the nerve root sedimentation sign in diagnosis of umbar canal stenosis, was discussed in the University of Basrah / College of Medicine. The aim of the thesis was to evaluate the validity of this sign in the diagnosis of lumbar canal stenosis. The thesis concluded that the sedimentation sign have a high sensitivity and specificity in the diagnosis of lumbar canal stenosis, and recommended of using it in the diagnosis and surgical outcome of lumbar canal stenosis.