Introduction. Li-Fraumeni syndrome (LFS) is a hereditary familial predisposition to a wide range of certain, often rare, malignant diseases. Patients also have a heightened risk of developing secondary and even tertiary malignancies throughout lifetime. The most common are soft-tissue and bone sarcomas, breast cancer, brain tumors, adrenocortical carcinoma and acute leukemia. Syndrome is inherited as an autosomal dominant disorder. In most families with LFS have been identified germline mutations of tumor protein TP53 gene. To our knowledge, this is the second case report of LFS that has been reported in our country, so far. Case report. We present five members of the same family with malignant diseases typical for LFS. A woman at the age of 21 with recurrent astrocytoma and mediastinal liposarcoma. The mother of her father had breast cancer at the age of 45 and died at 52. The father's sister had osteosarcoma, died before 40. The older sister had rhabdomyosarcoma and liver cancer, died at 18. Their father was diagnosed with lung adenocarcinoma two years after the second daughter, at the age of 49. Genetic analysis identified a pathogenic, heterozygous germline mutation TP53 gene. He also has an 8-yearold daughter who has not been tested for LFS. Conclusion. Genetic analysis for LFS of all family members is required in patients with rare and multiple malignancies, frequent and early onset malignancies in the family. Screening for the detection of early cancer manifestation is key to prolonged survival in people with LFS.