This cross-sectional study on mitral valve prolapse (MVP) in Korean adults revealed a relatively low overall prevalence at 2.5% (5 of the 200 subjects). Three of 5 subjects with MVP were females and the majority (4 of 5 subjects) were under 30 years of age. All subjects with MVP had thoracic skeletal deformities (4 straight back syndrome and 1 pectus excavatum). All subjects with MVP did not have cardiac history and they were all asymptomatic except for one who had intermittent palpitation of mild degree.