This study compared the diagnostic value of Whole-Body Ultra Low-Dose computed tomography (WBULDCT) with that of Spinal Magnetic Resonance Imaging (SMRI) in identification of spinal bone marrow involvement in patients with Multiple Myeloma (MM). Thirty-five patients with histologically proven MM underwent WBULDCT and dedicated SMRI. Unenhanced WBULDCT was performed on a 256-slice scanner, with 120kV and 40mAs. SMRI was performed on a 15T magnet, with T1-turbo spin echo and T2-short tau inversion recovery sequences on sagittal plane. WBULDCT was compared with SMRI in terms of lesion detection, pattern and bone marrow involvement. The overall concordance between WBULDCT and SMRI in lesion detection was 767%, detecting (25/35) or excluding (8/35) involvement of the axial skeleton, while in 2/35 patients WBULDCT and SMRI were discordant in terms of axial skeleton involvement. The concordance in spinal distribution of lesions was 616% on cervical, 715% on dorsal, 864% on lumbar and 944% on sacral, while for the pattern of disease, it was 561% for the focal and 887% for the combined pattern. Cohen's kappa index was 085 (P<0001) assessing an excellent agreement. WBULDCT represents a useful diagnostic tool in the detection of spinal involvement of MM patients, offering detailed information about extra-axial involvement, which could be potentially missed with dedicated SMRI.