The authors report a case of Löffler's fibroblastic endocarditis complicating a toxocarosis infection. Parasitic infestation with toxocara canis is usually asymptomatic, but this was a very rare observation of cerebral involvement associated with symptomatic Löffler's endocarditis. This is an unusual form of restrictive cardiac disease constantly accompanied by prolonged hypereosinophilia. In addition to the classical signs of cardiac failure, an acute febrile illness imitating a connective tissue disease may be observed. Echocardiography helps diagnosis by showing endomyocardial fibrosis and adherent thrombosis at one or both ventricular apices. The management of cardiac failure should include, whenever possible, radical treatment of the hypereosinophilia. At an advanced stage, surgical endocardial decortication is the only means of improving symptoms and the prognosis of these patients.