Determining the size of the heart is important for evaluating cardiac patients, because the increase of the cardiac silhouette in the chest radiography can be indicative of heart disease. The vertebral heart size (VHS) method is useful because it allows objective assessment of the limits of cardiac silhouette, and can help assess cardiomegaly and document changes in heart size in response to treatment or disease progression. The aim of this study was to compare VHS values of Maine Coon cats (MCC) with values cited in the literature (7.5 ± 0.3 vertebrae) obtained in non Maine Coon cats (NMCC). Sixty three MCC underwent the physical examination, electrocardiography, echocardiography, laboratory tests (blood count, biochemistry, including liver and kidney function, and total T4), as well as measurement of blood pressure. Faced with normal results, the cats were positioned in right lateral decubitus (right laterallateral projection), to perform chest radiography. The radiographic examinations were performed using the Fuji computed radiography system. The values of VHS found in the animals of this study were 7.61 ± 0.34 vertebrae with a minimum of 6.9 and of maximum 8.5 vertebrae. Statistical analysis performed by Student’s t test identified a significant difference between the values obtained in this study with those in the literature (p = 0.03) for non Maine Coon cats. The highest values of VHS obtained in MCC may be associated with the size of this giant breed.