The pathologic findings in two patients with idiopathic annular submitral left ventricular aneurysms and coexistent Takayasu's aortitis are documented. The evidence of chronic persistent myocarditis in one patient and marked myocardial fibrosis in the other supports two theoretical possibilities: first, the aneurysms may have an inflammatory etiology and, second, a common inflammatory process may have accounted for both the myocardial and the aortic lesions.