This is a case report about a radiological sign appearing in the spinal x ray of a 58-year-old patient with sickle cell disease (SCD), who presented at the emergency department with lumbar pain. The “fish-vertebra” sign appears as biconcave lumbar vertebrae with bone softening in lateral and posterior–anterior radiographs of the spine as an exaggeration of the normal concavity of the superior and inferior surfaces of one or more vertebral bodies (fig 1).¹ The above vertebral changes, characteristic of SCD, are the result of ischaemia (due to micro-infarctions) of the central portion of the vertebral growth plate, with a consequent disturbance of vertebral growth.^2,3