Objectives: The aim of the study was to analyze the changes in cardiac function and myocardial contractility of donor and recipient fetuses with twin-to-twin transfusion syndrome (TTTS) subjected to selective laser photocoagulation of the communicating vessels (SLPCV), between and after the procedure. Finally, we verified if fetuses with Quintero's stage I TTTS presented with early impairment of myocardial contractility. Material and methods: We selected 77 consecutive women with twin pregnancies, whose both fetuses survived at least seven days post-SLPCV. Myocardial contractility of both fetuses was evaluated ultrasonographically, and their myocardial performance indices (Tei-Index values) and shortening fractions (SF) were determined. Results: In donor fetuses, the Tei-Index values for both right and left ventricle remained within the respective reference ranges both before the procedure and during a 7-day follow-up. A significant change in shortening fraction values for the left ventricle in recipient fetuses and the right ventricle of in the donors was observed during a 7-day follow-up. Conclusions: Comparison of the cardiac parameters of donors and recipients revealed significant differences in Tei-indices during the entire follow-up period. The group with Quintero's I stage TTTS included 74% of recipient fetuses with abnormal Tei-Index values for the right ventricle (mean 0.53).