Comparative genomic hybridization was performed on 38 primary laryngeal carcinomas divided into two groups according to the metastatic phenotype. DNA copy number changes were detected in 22 of the 38 cases (57.9%). Gains were most frequently observed at 3q, 8q, and 9q, and losses were found in decreasing order at 18q, 3p, and 4. The mean value of losses was 2.5 times as high in metastasizing primary tumors (23/38) as in nonmetastasizing tumors. The most frequent losses in metastasizing tumors were at 18q, 3p, and 5q.