The pathogenesis of alcoholic cardiomyopathy (ACM) is not well understood. However, recent reports have shown that mutations in mitochondrial DNA (mtDNA) were associated with mitochondrial encephalomyopathy and cardiomyopathy. Our objective was to explore point mutations in mtDNA and the pathogenesis of ACM. We obtained heart biopsy specimens from ten male habitual drinkers with congestive heart failure. We amplified the total mtDNA obtained from these specimens using a two-step polymerase chain reaction method and analyzed the products using automated fluorescence-based direct sequencing. The sequences were compared with those of controls. MtDNA from the ACM patients contained multiple point mutations. Specifically, four of the ten patients carried five point mutations that had been detected previously in several other mitochondrial diseases. These point mutations were not observed in controls. These results suggest that mtDNA abnormalities are involved in the pathogenesis of ACM.