This report describes a case of cardiomyopathy associated with excessive moderator bands in a 7 years old cat. In the cat echocardiography examination was observed cardiomegaly, decreased systolic function and thinning of the left ventricle wall. The electrocardiogram showed the occurrence of supraventricular tachycardia. The treatment was initiated with digoxin, furosemide and taurine supplementation, with an improvement of the clinical signs, however the animal died in a fall. The diagnosis of cardiomyopathy associated with excessive moderator band, was based on the multiple cardiac bunds which connect the septum to the free wall of the left ventricle observed in the cat necropsy.