Background: Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytic tumor, accounting for <1% of astrocytic tumors. Due to its rarity, etiology, natural history, and biologic behavior is not completely explained. We present a case of malignant transformation of a PXA to glioblastoma in pregnant patient 6 month after tumor biopsy. ----- Case description: A 28-year-old female patient was presented with a newly onset of headache, nausea, and right-sided hemiparesis at 21st week of pregnancy. Magnetic resonance imaging (MRI) revealed cystic mass in the left frontal region. Patient underwent biopsy to confirm pathohistological analysis; the tumor tissue corresponded to an anaplastic PXA. Two weeks after initial biopsy, open surgery along with gross total tumor removal was performed confirming pathohistological analysis. Six months later, after childbirth, and control MRI revealed a recurrent tumor mass: the patient underwent surgical resection and the tumor tissue corresponded to a glioblastoma. The patients were further treated with radiation and chemotherapy according to oncologist. ----- Conclusion: Distinguishing between PXA patients who have a good prognosis and those at risk for early progression is very important for the PXA clinical management. Despite cellular pleomorphism, mitotic index and the extent of resection are shown to be the main predictors for recurrence-free survival and overall survival rates. The standard therapy management is not yet established. Our patient treatment was associated with a significant ethical dilemma. Respecting patient's wishes to deliver a baby, nor radio or chemo treatments were done. Further studies are necessary to provide factors responsible for malignant transformation of PXA. In addition, in ethically sensitive situation, such as tumor in pregnant patient, good communication, respecting patient's wishes, and a multidisciplinary teamwork is the key for better outcome.