We report the finding of clonal structural chromosome abnormalities in short-term cultures from 15 squamous cell carcinomas of the head and neck region. When the distribution of chromosomal breakpoints in these 15 tumors and in the 16 head and neck carcinomas previously described are assessed, a marked clustering is seen at bands 1p22 and 11q13, which are rearranged in eight and nine tumors, respectively. No other band was involved in aberrations in more than five tumors. Cytogenetic evidence of gene amplification was seen in four tumors, three times in the form of homogeneously staining regions (twice located in 11q13), and in one tumor as double minutes. Among the candidate genes for such amplification are BCL1, INT2, and HST1, all of which map to 11q13, and NRAS, which maps to 1p22. All these oncogenes have previously been shown to be amplified in subsets of head and neck carcinomas. We conclude that bands 1p22 and 11q13 are nonrandomly involved in chromosomal rearrangements in head and neck carcinomas and suggest that activation of oncogenes located in these bands may proceed via cytogenetic mechanisms.