Background: Heart failure is a major cause of morbidity and mortality worldwide; left ventricular diastolic dysfunction plays a leading role in this clinical context. Diastolic dysfunction may be predisposed by increased abdominal fat and, consequently, increased pericardial and epicardial adiposity. This study aimed to determine whether pericardial and epicardial fat are associated with left ventricular diastolic function. Methods: 82 patients had their abdominal circumference measured and underwent transthoracic echocardiography to measure the thickness of pericardial and epicardial fat and assess the left ventricular diastolic function. Two groups were created based on mean pericardial fat thickness (4.644 mm) and were related to abdominal circumference and echocardiographic parameters. Results: Subjects in the PF High group showed a significant decrease in septal e' (p<0.0001), lateral e' (p<0.0001) and E/A ratio (p=0.003) and a significant increase in E/e' ratio (p<0. 0001), E wave deceleration time (p=0. 013), left atrial volume (p<0.0001), LV mass (p=0.003), tricuspid regurgitant jet velocity (p<0.0001) and LV diameter (p=0.014) compared to the PF Low group. Conclusions: Measurement of abdominal circumference, pericardial and epicardial fat is an early indicator of diastolic changes with transthoracic echocardiography being the gold standard exam.