The presence of gene amplification was determined in 66 fresh head-and-neck SCC specimens using a battery of 9 different probes. Amplification of at least one gene was found in 12 samples (18%), of which 7 were amplified at multiple loci (58%). We observed amplifications for EGFR (10% of samples) and c-myc (9%), as well as co-amplification of bcl-1/int-2 (7%). No amplifications were demonstrated for c-Ha-ras-1, TGF alpha, c-mos, c-erbB-2, or c-erbA-2. The incidence of proto-oncogene amplification in head-and-neck SCC patients is comparable to that reported for other solid tumours. There was no statistically significant difference in survival between patients with or without gene amplification. However, the presence of multiple amplifications in several patients with advanced primary tumours suggests that the accumulation of genetic changes may correlate more closely with tumour size than with inherent biologic aggression.