Prosthesis valve dehiscence is one of the most serious complications of prosthetic valves. Despite the improvements in medical and surgical treatments, prosthesis valve dehiscence has high mortality. Due to fatality rates, the early diagnosis and treatment of these patients is required. In this case report, we presented a patient with severe mitral deficiency and acute heart failure following mechanical mitral prosthesis valve dehiscence secondary to culture-negative endocarditis.