A case of delayed intracerebral abscess due to Proprionibacterium acnes (P. acnes), 18 months after an uneventful excision of a parasagittal haemangiopericytoma in a 61-year-old female is reported. This is highly unusual as cerebral abscess by P. acnes is rare and it occurred so late postoperatively in the absence of known risk factors. We propose the inclusion of cerebral abscess by P. acnes in the differential diagnosis of lesions that mimic tumour recurrences, after clean craniotomies.