We report a 26-yr-old female patient with bilateral breast cancer who was clinically diagnosed with Li-Fraumeni like syndrome (LFL) and subsequently found to have a germline mutation of the TP53 gene. The patient was initially diagnosed with right breast cancer at age 24 yr and then with left breast cancer at age 25 yr. Surgery and radiotherapy were performed accordingly. The patient had a family history of various types of early onset cancers and was referred to a genetic counseling clinic. She was clinically diagnosed with LFL. Genetic analysis of the TP53 tumor suppressor gene was performed with the patient's consent. Direct sequencing of TP53 gene exons 5, 6, 8, 9, and 11 revealed a ermline missense mutation, resulting in an amino acid change from an arginine to a histidine (g.13203G>A, p.R175H). Considering the family history, individualized cancer surveillance was performed including a gastroscopy and a brain MRI. Even though the patient had not shown any neurological symptoms, a huge mass on the temporal lobe was incidentally found and the patient received surgery and radiotherapy. Although the residual mass required further treatment, the patient decided on supportive care alone and was discharged. We report a case of LFL, with a germline TP53 mutation, which was confirmed by gene sequencing in Korea. This case shows how genetic predisposition screening and counseling in patients, suspected of having a familial cancer syndrome, can influence the course of the patient.