Spinal actinomycosis is a rare infection that usually develops from contagious spreading of the causative organism. Diagnosing this malady may be delayed due to the nonspecific radiological findings and the slow progression of the disease. We present here the case of a 51-year-old male with slowly progressing lower back pain and fever. Computed tomography (CT) and magnetic resonance (MR) imaging revealed a paraspinal mass and cortical destructive change in the L1 vertebra, but the disk space was spared. A surgical biopsy confirmed spinal actinomycosis. We describe the CT and MR imaging findings of this patient and we also review the related literature to highlight this uncommon disease entity.