Mutations in the mitochondrial ATPase6 gene are frequent in human osteosarcoma. To explore the polymorphisms and mutations of mitochondrial ATPase6 gene in Chinese patients with osteosarcoma and their possible association with carcinogenesis, direct DNA sequencing method was used to detect the variants of the mitochondrial ATPase6 gene in 39 patients with osteosarcoma. We found mutations of the mitochondrial ATPase6 gene in 24/39 (61.5%) of the tested osteosarcoma samples, and identified 27 variant sites in ATPase6 coding regions. We did not detect any new polymorphisms in osteosarcoma, nor was there any association between variants and the three histopathological subtypes. These data demonstrated that mtDNA mutations within the ATPase6 gene are a frequent event in Chinese patients with osteosarcoma.Copyright © 2012. Published by Elsevier Inc.