We report a study of a 22-year-old woman with a plasma-cell granuloma (PCG), a rare intracranial lesion characterized by a non-neoplastic polyclonal proliferation of plasma cells and other mononuclear cells. She presented after a generalized seizure and CT-scan and magnetic resonance images demonstrated a left temporo-basal tumour mass involving both the meningeal layers and the brain parenchyma. Histopathological examination of a biopsy led to the diagnosis of a typical PCG. After a short course of steroid administration, the clinical and radiological features improved and complete regression of the lesion was shown after one year and persisted at four-year follow-up. This dramatic regression of an intracranial PCG shows that neither surgical removal nor radiation therapy is required to treat a broad skull base PCG.