The karyotypes of head and neck cancer usually display complex chromosomal aberrations. There is no specific aberration in this type of cancer, although the rearrangement of chromosome 11 involving the band 11q13, often with its amplification, seems to be significant. Unfavourable prognostic factors are complex karyotype, aneuploidal DNA content and the rearrangement or amplification of 11q13 and are associated with shorter survival. Diploid DNA content is prognostically favourable in this type of neoplasm.