BACKGROUND: Cardiomyopathies are myocardial disorders in which the heart muscle is structurally and functionally abnormal. Several mutations in sarcomere protein coding genes are responsible for different types of cardiomyopathies. ACTC1 is one of the main sarcomere components in heart muscle. Two mutations of E101K and M123V in this gene are shown to be associated with cardiomyopathies. METHODS: In this case and control study, a sample of contains 30 hypertrophic cardiomyopathy and 100 dilated cardiomyopathy patients, as well as 130 healthy individuals were screened for two mutations of E101K and M123V. The genotypes of samples were determined in whole blood genomic DNA by restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) and mismatched-PCR-RLFP techniques. RESULTS: All patients and healthy peoples had wild type genotype for both locations and even no heterozygous was detected. CONCLUSION: Despite previous reports, no association was observed between both mutations with cardiomyopathy. Our results indicated that two mutations of E101K and M123V of ACTC1 gene may are not associated with cardiomyopathy in Iranian population.