The Li-Fraumeni syndrome (LFS) is characterised by an autosomal dominant hereditary predisposition to cancer. Affected individuals suffer from sarcomas, breast and brain tumours, and adrenocortical carcinomas, but also from other types of tumours. The cancers may arise at an unexpectedly young age, often in early childhood, and the patients may suffer from several independent tumours. Some of the affected families harbour a germline mutation in the tumour suppressor gene TP53. These mutations can also be found in some families not conforming to the strict criteria of LFS. All individuals at risk should undergo a regular follow-up, because early diagnosis of cancer may also in LFS lead to amore successful tumour therapy. Screening for germline TP53mutations can confirm or exclude the cancer predisposition in individual family members. Oncogenetic counselling is associated with many psychological and ethical problems. Interdisciplinary collaboration between clinicians and geneticists as well as involvement and collaboration of the patients and their relatives is needed for an optimal care for families at risk.

        Key words: Li-Fraumeni syndrome, germline TP53 mutations, hereditary predisposition to cancer, cancer family, childhood cancers, anticipation, oncogenetic counselling, preventative follow-up