Nine striped dolphins Stenella coeruleoalba and 1 bottlenose dolphin Tursiops truncatus stranded along the Ligurian Sea coast of Italy were necropsied between February 2011 and April 2012. Macroscopic and histological findings were observed in the hearts of all animals and included saccular aneurysms of the pulmonary trunk (n = 3), cirsoid aneurysms (n = 1), right ventricular dilation (n = 1) associated with hypoplasia of the tricuspid chordae (n = 1), valvular fibrosis (n = 3), mitral leaflet thickening (n = 1), left ventricular hypertrophy (n = 1), lymphocytic myocarditis (n =1), and Lambl's excrescences (n = 4). To our best knowledge Lambl's excrescences, aneurysm of the pulmonary trunk, and cirsoid aneurysms have not previously been described in marine mammals, and some of these findings should be taken into account as possible causes of dolphin morbidity, mortality, and stranding.