Calcific diskitis (CD) is a rare condition characterized by inflammation and calcification of an intervertebral disk, typically causing localized back pain. We present the case of a 65-y-old woman with a history of breast cancer and persistent back pain. SPECT/CT identified focal uptake at the T10-T11 vertebrae, localized to the intervertebral disk. Retrospective review of MR images from 2016 demonstrated a hypointense signal within the same disk on both T1- and T2-weighted images, consistent with disk calcification. This case highlights the utility of SPECT/CT in identifying CD and distinguishing it from other pathologies, including metastatic or degenerative spinal disease. CD should be considered in the differential diagnoses of backache.