We report a previously healthy 47-year-old woman suffering acute embolic stroke in the left middle cerebral artery distribution. A filiform hypermobile mass along the line of the aortic valve representing a Lambl's excrescence was first identified by transesophageal echocardiography. Lambl's excrescences are structures attached to the edges of cardiac valves that have been associated with stroke, although their exact pathogenetic mechanisms have not yet been established. Further, treatment after cryptogenic stroke associated with presence of a valvular strand is based on platelet inhibition. Following currently available evidence, surgery cannot be generally recommended for this condition.