Spontaneous dehiscence of the aortic wall at the aortic commissure is not recognized as one of the usual pathological causes of aortic regurgitation. We describe the case of a 56-year-old man with hypertension, who experienced acutely progressive congestive heart failure due to massive aortic regurgitation. Local layer dehiscence around the commissure was noted with partial detachment of the commissure resulting in the loss of commissural support with secondary rupture of a non-coronary cusp, which led to massive aortic regurgitation.