Ovarian cancer is one of the most frequent gynecological malignancies worldwide with a poor prognosis. Comparative genomic hybridization has been applied to detect recurrent chromosome alterations in 31 primary ovarian carcinomas in Chinese women. Several nonrandom chromosomal changes were identified including gains of 3q (17 cases, 55%) with a minimum region at 3q25 through q26, 8q (16 cases, 52%), 19q (12 cases, 39%), Xq (11 cases, 35%), 1q (10 cases, 32%), 12p12 through q13 (10 cases, 32%), 17q (10 cases, 32%) with a minimum gain region at 17q21, and 20q (9 cases, 29%); and losses of 16q (9 cases, 29%), 1p (7 cases, 23%), 18q (7 cases, 23%), and 22 (7 cases, 23%). High-copy-number amplification was detected in eleven cases. Amplification of 3q25 through q26 was detected in four cases, and amplifications of 8q24 and 12p11.2 through q12 were observed in three cases each. The recurrent gains and losses of chromosomal regions identified in this study provide candidate regions that may contain oncogenes or tumor suppressor genes involved in the development and progression of ovarian cancer.