We present the rare case of a 31-year-old man who developed a germinoma 22 years after resection of a mature teratoma of the pineal region. The initial stereotactic biopsy showed a granulomatous inflammation, but no malignant cells. The correct diagnosis could only be confirmed in a second cerebral biopsy, allowing for proper treatment with radiation therapy. The need to consider metachronous germinoma in this setting is discussed.