Vascular involvement is one of the major characteristics of Behcet's disease (BD). However, there are controversial findings regarding cardiac involvement in BD. Although early reports demonstrated that there is diastolic dysfunction in BD, conflicting results were found in the following trials. Hence, a new method for more objectively estimating the cardiac functions is needed. For this aim, we used high-usefulness tissue Doppler echocardiography for detailed analysis of cardiac changes in BD patients because this method was superior to other conventional echocardiographic techniques. The study population included 42 patients with BD (19 men, 23 women; mean age, 35 +/- 10 years, mean disease duration, 2.7 +/- 1.6 years) and 30 healthy subjects (14 men, 16 women; mean age, 38 +/- 7 years). Cardiac functions were determined using echocardiography, comprising standard two-dimensional and conventional Doppler and tissue Doppler imaging (TDI). Peak systolic myocardial velocity at mitral annulus, early diastolic mitral annular velocity (Em), late diastolic mitral annular velocity (Am), Em/Am, and myocardial performance index (MPI) were calculated by TDI. The conventional echocardiographic parameters and tissue Doppler measurements were similar between the groups. Tissue Doppler derived mitral relaxation time was longer (75 +/- 13 vs 63 +/- 16 msn, p=0.021) in patients with BD. There was statistically significant difference between the two groups regarding left ventricular MPI (0.458 +/- 0.072 vs 0.416 +/- 0.068%, p=0.016), which were calculated from tissue Doppler systolic time intervals. There was also significant correlation between the disease duration and MPI (r=0.38, p=0.017). We have demonstrated that tissue Doppler-derived myocardial left ventricular relaxation time and MPI were impaired in BD patients, although systolic and diastolic function parameters were comparable in the patients and controls.