The aim of this study was to assess the association between mitral annular calcium (MAC) and flail mitral leaflets in a cohort of patients with degenerative mitral valve disease. A retrospective study was conducted of consecutive patients with degenerative mitral valve disease who underwent echocardiography at Rabin Medical Center from 2003 to 2012. Special focus was attended to the presence and grade of MAC and characterization of valve pathology (myxomatous vs nonmyxomatous, prolapse vs flail). Patients were excluded if they had undergone previous mitral valve surgery and/or had infective endocarditis. Multivariate logistic regressions were used to control for confounders. The study included 1,912 patients (60.8% men, mean age 63.8 ± 17.4 years) divided into 3 groups: 1,627 (86%) without MAC, 183 (10%) with either mild or moderate MAC, and 94 (5%) with severe MAC. The presence of flail leaflet was 27%, 30%, and 46% in these groups, respectively (p <0.001). After adjustment for age, gender, and co-morbidities, the odd ratio for flail mitral leaflet with severe MAC versus no MAC was 1.76 (95% confidence interval 1.10 to 2.83, p = 0.019). In conclusion, this study demonstrates that degenerative mitral valve disease with severe MAC is significantly associated with flail mitral leaflet.