Purpose: Recovery to near normal left ventricular (LV) systolic function is often observed in patients with idiopathic dilated cardiomyopathy (DCMP). This study aimed to investigate whether cerebral blood flow (CBF) might be associated with recovery of ventricular dysfunction. Methods and Results: One hundred and seven patients diagnosed with idiopathic DCMP underwent radionuclide angiography to obtain CBF between July 2001 and March 2009. The recovery of LV systolic function was defined as recovery of ejection fraction (EF) measured by transthoracic echocardiography to a level of 40% or greater and an increase of 10% or greater in absolute value during follow-up. When not recovered, EF was followed up for at least 36 months or more. Cardiac transplantation or death was regarded as cases of irreversible LV systolic dysfunction. 34 patients (31.8%) were recovered and they had more augmented CBF than irreversible patients (41.9짹3.4 vs. 37.1짹4.9 ml/min/100g, p<0.001). Using a multivariate binary logistic model, CBF (odds ratio 1.20) and symptom duration (odds ratio 0.94) were independent predictors of LV functional recovery. There was negative correlation between CBF and symptom duration (r=-0.334, p=0.001, Figure 1). Clinical, echocardiographic, and CBF parameters were investigated for their predictive value of LV function improvement when 1 year and 2 years after enrollment. 57 patients underwent transthoracic echocardiography between 10 and 14 months (defined as 1-year follow-up) and 39 patients underwent the test between 22 and 26 months (defined as 2-year follow-up). On multivariate linear regression analysis, CBF was independently associated with LV EF improvement (��LV EF=baseline LV EF–LV EF at the follow-up time) and LV EF at 1 year and 2 years after enrollment (Figure 2). Conclusion: CBF, the indicator of the chronicity of heart failure, was associated with recovery of LV systolic dysfunction in patients with idiopathic DCMP.