Background: Little was known about the regional wall motion of the left ventricle (LV) in fetus, especially whether a fetal myocardium twist. Aim: The purpose of this study is to determine the feasibility of measurement of the twist of LV in fetus, by using velocity-vector-imaging (VVI), as a new imaging modality of two-dimensional tissue tracking. Subjects: 9 normal fetuses with normal ejection fraction from 29 to 38 weeks of gestation. Methods: Diagnostic apparatus was Sequoia 512 (Siemens Medical Systems) with 8-3MHz probe. The short axial B-mode images of LV each at cardiac base and at apex (frame rate >80fps ) were obtained with maternal ECG-triggering then digitally stored. Data were analyzed by off-line Syngo program (Siemnes MS). Endodiastolic frame of fetal LV was determined as the frame at the longest internal diameter by M-mode. The border of endocardium (End) and epicardium (Epi) was manually traced then automatically tracked by Syngo sytem to calculate the rotational angles. LV twist was calculated by subtracting the averaged rotational angle of cardiac apex from that of cardiac base along a cardiac cycle. Results: In fetuses, the peak-twist was 7.16 ±3.1 degree in End and 5.6±2.7 degree in Epi, respectively. The peak twist was not changed along gestational age. Conclusion: The LV of fetus does twist in same fashion as that of an adult but the peak-twist of the LV in fetus is about a half of that in adult ( 13.3+/- 0.3 degree) and is not changed along the gestational age.