Li–Fraumeni syndrome (LFS) is defined by the early emergence of tumors and is associated with mutations in the tumor suppression gene known as tumor protein 53 ( TP53). Information is scarce regarding the psychosocial challenges encountered by individuals with LFS and how it affects their treatment decisions. A 21-year-old woman developed multiple breast tumors over a period of nine years. Genetic testing identified a heterozygous missense substitution in exon 6 of the TP53 gene, specific variant chr17:7578190T>C c.659A>G (p.Tyr220Cys) listed in the dbSNP database. The report also highlights the psychosocial implications of the diagnosis at a young age and the patient’s reluctance to undergo the recommended bilateral mastectomy. The patient exhibited a significantly higher incidence of secondary tumors, underscoring the importance of comprehensive screening and timely diagnosis for managing LFS. This case highlights the challenges faced and the importance of emotional and psychological support after the diagnosis of hereditary syndromes, especially among young women.