Native valvular emergencies are nearly always regurgitant in nature, whereas acute prosthetic valve dysfunction can be either regurgitant or stenotic. Regardless of the etiology, the presentation of acute valvular pathology differs significantly from chronic disease in both clinical presentation and in its appearance on diagnostic modalities, and appropriate recognition is critical to the choice of the appropriate therapeutic modality. Intrinsic to the recognition of a valvular emergency is a knowledge of those conditions for which a high index of suspicion must be maintained. This article addresses the etiologies, presentation, and diagnosis of these conditions and presents the relevant data that bears on which therapy may be most appropriate for which condition.