Background Li-Fraumeni syndrome (LFS) is a rare autosomal dominant cancer predisposition syndrome caused by germline TP53 gene mutations. It is characterized by high risk of early-onset cancer, and has been confirmed as associated with multiple tumors clinically. So pediatricians should be more alert to LFS in children with tumors. Choroid plexus carcinoma (CPC) is a rare, malignant tumor which account for less than 1% of all central nervous system (CNS) tumors. However, when such tumorigenesis occurs, it is important to be vigilant for the presence of LFS. Case presentation The first patient is a 32-month-old boy admitted for convulsions and then was found intracranial space-occupying lesion. Underwent operation, he was diagnosis as choroid plexus carcinoma (WHO Grade III). After 5 months, his elder sister, a 13-year-old girl, was brought to emergency department for confusion and intermittent convulsions. Surgery was performed immediately after head CT examination found the lesion. The pathology result indicated glioblastoma. Because the siblings of the same family have successively suffered from malignant tumors, we performed genetic testing on this family. TP53 gene mutation occurred in both children of these two cases from their father, and their other brother was not spared either. So the two siblings both met the diagnostic criteria of LFS. Then they all received systematic anti-tumor therapy, and follow-up hitherto. Conclusion Here we reported a rare LFS case that two siblings were inherited the same TP53 germline mutations from their father. They suffered from choroid plexus carcinoma and glioblastoma and were finally diagnosed with LFS. In this LFS family, the primary tumors of the two children were both central nervous system tumors, which were not reported in the previous literature. It is suggested that clinicians should be alert to LFS related tumors, which is helpful for early diagnosis. Timely detection of TP53 gene is an important way for early diagnosis of LFS, especially in children with tumor. The incidence of secondary tumor in LFS patients is significantly higher, and other family members of the LFS patient also have an increased risk of suffering from the tumors. Therefore, early diagnosis and timely tumor surveillance can obtain better therapeutic effect and prognosis for both proband and their family.