: Although meningiomas are typically solitary lesions, occasionally, two or more separate tumors can occur simultaneously or sequentially, in which case the terms "multiple meningiomas" (MM) or "meningiomatosis" are used. Aggressive meningiomatosis is a rare entity that can significantly influence survival rates and quality of life. : The current article aims to report an interesting case of a 54-year-old Caucasian woman with aggressive meningiomatosis and no relevant familial history. The patient had a history of a left convexity frontal meningioma, resected in October 2023 and identified as a meningothelial meningioma, followed by a left convexity frontopolar meningioma, resected in May 2024 and identified as an anaplastic meningioma. Furthermore, while the first lesion rapidly recurred, an important change in the histopathological grade was observed, and a diagnosis of aggressive meningiomatosis was established. : The particularity of this case is given not only by the aggressive growth pattern but also by the different histopathological gradings of the meningiomas and the anaplastic transformation of the recurrence. : Aggressive meningiomatosis is a challenging medical condition for which rigorous follow-up is mandatory throughout the lifespan. New tumors with different gradings and localizations can arise, and each must be treated as a new entity. The lack of therapeutic protocols in MM makes such case reports valuable, as they highlight the necessity of specific therapeutic recommendations.