Chromosomal aberrations were investigated in 48 Korean nonsmall cell carcinomas of the lung (NSCLC), by degenerate oligonucleotide primed polymerase chain reaction comparative genomic hybridization. These included 16 adenocarcinomas, 27 squamous cell carcinomas (SCCs), and 5 large-cell carcinomas. The common sites of copy number increases were 3q26 approximately qter (23 cases, 48%); 8q23 approximately qter (46%); 20q13.1 (42%); 1q42 approximately qter (38%); 3q25 (38%); 21q22 (38%); and 22q13 (38%). DNA amplification was identified in 19 carcinomas (40%), and the frequent sites of amplification were 8q24 (seven cases), 3q26 (seven cases), and 3q27 (seven cases). The frequently under-represented chromosomal regions were Yq (38%), 4q25 approximately q26 (23%), and 4q31 (23%). In particular, gains of 3q26 approximately qter (74%), 15q (56%), and 19q (59%) and loss of 13q22 approximately q31 (26%) were more frequently detected in SCCs of the lung. These nonrandom aberrations can serve as starting points for the identification of potential oncogenes/tumor suppressor genes related to the tumorigenesis of Korean NSCLC.