Paravalvular leak (PVL) is a frequent complication of transcatheter aortic valve replacement (TAVR) that occurs at a much higher rate after TAVR than after conventional surgical aortic valve replacement. Recent reports indicating that PVL may be associated with increased late mortality have raised significant concern. However, the heterogeneity of methods for assessing and quantifying PVL, in addition to lack of consistency in the timing of this assessment, complicate the understanding of its true prevalence, severity, and clinical implications. The following review is an effort to consolidate current knowledge in this area in order to better understand the incidence, progression, and clinical impact of post-TAVR PVL, as well as to focus future research efforts on the assessment, prevention, and treatment of this important complication.