Abstract Purpose To evaluate pre- and post-procedure myocardial function in monochorionic twins with TTTS who underwent laser ablation of placental anastomoses using pulsed wave tissue Doppler imaging (pw TDI). Materials and Methods 20 monochorionic twin gestations with TTTS were included and underwent laser ablation at our center between 2011 and 2014. Prior to and after the intervention, cardiac function was assessed by measuring the mitral annular plane systolic excursion (MAPSE), the tricuspid annular plane systolic excursion (TAPSE), Tei index, isovolumetric contraction time (ICT), ejection time (ET), isovolumetric relaxation time (IRT) for the left ventricle in pulsed wave Doppler (pw D) ultrasound as well as ICT, ET, IRT and Tei index in pw TDI for the left and right ventricle. E-, A-, E´- and A´-wave peak velocity and the systolic downward motion (S´) were measured for both ventricles and the E/A, E/E´ and E´/A´ ratios were calculated. In a mean of 1.3 (SD 0.6) days after laser ablation, this measurement protocol was repeated. Results Pre-intervention recipients had longer ICT, ET and IRT in pw D and pw TDI compared to donors not reaching statistical significance for most parameters. Statistically significant were prolonged ICT in pw D (p 0.01) and ET (p 0.01) in pw TDI in recipients. In donor fetuses preoperative myocardial function did not differ significantly from postoperative myocardial function except in increased left ventricular ejection time of the left ventricle in pw TDI (p 0.04) and an increased E´/A´ratio (p 0.01). After laser coagulation, myocardial function was slightly altered in recipients as ICT and IRT shortened and Tei indices decreased but only reaching statistical significance in shortened IRTs in pw TDI for both ventricles. Conclusion Laser ablation of placental anastomoses in TTTS might influence myocardial function in the postoperative period. Shortened IRT intervals may reflect an improvement of diastolic function in recipients.