Patent foramen ovale (PFO) is a common finding in healthy adults and has long been implicated in cryptogenic stroke. The pathogenesis is hypothesized to be caused by microemboli gaining access into the systemic circulation via a PFO. Proposed treatment options include medical therapy and/or PFO closure. Despite numerous studies and several randomized trials, much debate persists regarding the efficacy of this approach in reducing the risk of recurrent stroke in cryptogenic stroke patients. This article reviews the association between PFO and cryptogenic stroke, as well as current evidence for PFO device closure.