OBJECTIVE To investigate the properties of paraspinal muscle structures in osteoporotic patients, lumbar computed tomography (CT) and their relationship with lumbar and femoral neck bone mineral density (BMD). METHODS A Descriptive study. METHODS Department of Radiology and Physical Medicine, Istanbul Medeniyet University, Goztepe Prof Dr Suleyman Yalcin City Hospital, Istanbul, Turkey, between June 2020 and June 2021. METHODS Ninety patients with osteoporosis, who received lumbar spine CT and dual-energy X-ray absorptiometry (DEXA) examinations, were retrospectively included. Cross-sectional areas (CSA), densities, index values, and Hounsfield unit average calculation(HUAC) values were measured for psoas, multifidus, erector spinae, and quadratus lumborum muscles at the L3 level, and their associations with BMD were investigated. RESULTS A total of 90 patients including 71 females were evaluated. The mean age was 63.31±11.90 years. A moderate correlation of lumbar spine (r=0.32, p<0.01) and femur neck BMD (r=0.28, p<0.05) with erector spinae CSA was defined. Small correlation between psoas CSA (r=0.28, p<0.05) and psoas muscle index (PMI, r=0.24, p<0.05) with lumbar spine BMD was found. The CSA of all the paraspinal muscles (p<0.01) and densities, except psoas muscle (p<0.05), were higher in males. In non-obese osteoporotic patients, the density and HUAC values of the paraspinal muscles, except the psoas muscle, were found to be significantly higher (p<0.05). CONCLUSIONS The properties of the paraspinal muscles measured by the lumbar CT scan are found to be related to BMD. The psoas and erector spinae CSA and index values are the most significantly associated parameters with the lumbar spine BMD. BACKGROUND Bone mineral density, Computed tomography, Osteoporosis, Paraspinal muscles, Psoas.