Objectives: To evaluate the association of diastolic function of the left ventricle with flowme-diated dilatation (FMD) in uncomplicated Type 2 diabetes mellitus patients. Methods: Eighty-two uncomplicated Type 2 diabetic patients were examined by pulse and tissue Doppler echocardiography and FMD of brachial artery. The patients were divided into 2 groups according to the size of the left ventricular relaxation parameter—E’. Results: The average age of the patients was 61 ± 6 years. FMD was 5.0 ± 1.8% in 41 patients with E’ from 3 to 7.4 cm/s (mean 6 cm/s) comparing to 5.1 ± 1.9% (p = 0.96) in 41 patients with E’ from 7.5 to 10.9 cm/s (mean 8.9 cm/s). E/E’ was 11.2 ± 2.3 in the group with lower E’ and 9.1 ± 1.6 in the group with higher E’ (p < 0.001). Linear negative correlation was found between E/E’ and FMD for the patients with E’ from 3 to 7.4 cm/s (R² = 0.131; p = 0.025) but not for the group of patients with the higher E’. The significant association between FMD and E/E’ was confirmed by multivariate analysis ((R^c)² = 0.233; p < 0.05). Conclusion: FMD has no impact on the left ventricular relaxation. However FMD is negatively associated with E/E’ in Type 2 diabetic patients who have low E’ as a sign of an impaired early relaxation.