Background: Anemia plays an important role in the development of cardiovascular structural and functional alterations. There has been little previous data to review on the effect of low hemoglobin level on the left ventricle in patients without heart diseases. The objective of this study was to document changes in echocardiographic variables of left ventricular size and function after correcting for anemia. Methods: Fifteen iron deficiency anemia patients (39짹8 years old, all females) without traditional cardiovascular risk factors and cardiovascular diseases were studied. Before and after iron replacement therapy, echocardiographic studies were carried out to evaluate their left ventricular structure and function by M mode, two-dimensional and Doppler images. Results: The mean length of iron replacement therapy was 4.5짹2.0 months. Hemoglobin levels increased on follow up compared with its baseline (5.5짹1.3 g/dL vs 12.5짹1.8 g/dL, p=0.001). There were significant decreases in the followings: Left ventricular end-diastolic dimension (52.5짹4.0 vs 50.1짹3.8, p=0.021), left ventricular end-systolic dimension (31.7짹3.1 vs. 29.7짹3.1, p=0.015), left ventricular mass index (107.5짹30.4 vs 88.1짹24.6, p=0.001), left atrial volume index (29.7짹10.6 vs 25.1짹5.1, p=0.026). Left ventricular ejection fraction did not differ significantly (64.3짹4.6 vs 64.5짹5.3, p=0.649). In the Doppler echocardiographic studies, indices for diastolic dysfunction, E velocity (106.1짹25.3 vs 80.8짹17.7, p=0.003) and E/E'(8.9짹2.4 vs 7.3짹1.4, p=0.003) also decreased. Conclusions: Appropriate correction of low hemoglobin level improved ventricular diastolic function and reduced left ventricular volume and muscle mass.