Diagnostics of diseases of the lumbar part of spine in elderly and senile people is difficult due to their polyethiologics, similarity of clinical currents accompanied by both pathological and age changes in an organism essentially deforming a clinical picture of a disease. Having used the experience of treatment of 2102 patients with low-back pain, the authors worked out the schemes of differential, thopical and X-ray diagnosis. All that will enable the practice doctors to diagnose the diseases in proper time and to determine the proper way of inquiry and treatment.