BACKGROUND Mitral annular calcification (MAC) is increasingly observed in elderly population. The purpose of this study was to investigate incidence of MAC and its association with mitral valvular disease (MVD). METHODS A total of 13,483 consecutive patients who underwent echocardiography were enrolled. MAC was defined as an echo-dense, shelf-like structure with an irregular, lumpy appearance involving the mitral valve annulus, with acoustic shadowing. Prevalence of MAC and its association with significant mitral stenosis (MS) or mitral regurgitation (MR) were studied. Significant (≥moderate) MS was defined as mean transmitral valvular pressure gradient > 5 mm Hg and significant MR was defined as ≥moderate MR based on quantitative or semi-quantitative Doppler methods. RESULTS MAC was present in 1881 of 13,483 patients (14%). Patients with MAC (MAC group) was older and more female gender than those without MAC (non-MAC group). Significant MS was present in 2.2% of MAC and in .6% of the non-MAC group (p < 0.0001). Significant MR was present in 11.9% of MAC and in 5.0% of the non-MAC group (p < 0.0001). Co-existence of MAC and aortic valve replacement (AVR) was associated with increased prevalence of MVD (MS:11.4%, MR:17.2%, respectively). CONCLUSION MAC was present in 14% of the patients and was associated with significant MVD. Co-existence of MAC and AVR may increase the risk of MVD.