Alterations in mitochondrial DNA (mtDNA) have been studied in various cancers. However, the clinical valueof mtDNA copy number (mtCN) alterations in gastric cancer (GC) is poorly understood. In the present study,we investigated whether alterations in mtCNs might be associated with clinicopathological parameters in GCcases. mtCN was measured in 109 patients with GC by real-time PCR. Then, correlations with clinicopathologicalcharacteristics were analyzed. mtCN was elevated in 64.2% of GC tissues compared with paired, adjacent, noncanceroustissue. However, the observed alterations in mtCN were not associated with any clinicopathologicalcharacteristics, including age, gender, TN stage, Lauren classification, lymph node metastasis, and depth ofinvasion. Moreover, Kaplan-Meier survival curves revealed that mtCN was not significantly associated with thesurvival of GC patients. In this study, we demonstrated that mtCN was not a significant marker for predictingclinical characteristics or prognosis in GC.