Bicuspid aortic valve (BAV) malformations and rupture of the aortic valve chordae tendineae can independently cause aortic regurgitation; however, their coexistence in a single patient is rare. This article reports on a 35-year-old male patient who presented with sudden breathing difficulty, and transthoracic echocardiography revealed only prolapse of the right coronary cusp of the aortic valve with severe regurgitation. This indicates the necessity of adopting a new diagnostic approach, namely transesophageal echocardiography, to clearly identify the disease etiology. The final diagnosis was a combination of partially fused bicuspid aortic valve (BAV) malformation and ruptured aortic valve chordae tendineae.