Objective: To compare the fetal modified myocardial performance index (Mod-MPI) in appropriately grown, early (EO) and late onset (LO) fetal growth restricted (FGR) fetuses and to assess its prognostic significance for adverse perinatal outcome. Study design: In a prospective case-control study, Mod-MPI was performed in 22 and 51 fetuses with EO and LO-FGR fetuses, respectively. Mod-MPI values of FGR fetuses were compared against gestation-matched controls (34 for EO-, and 32 for LO-FGR, respectively). Correlation testing related with poor perinatal outcomes were performed. Results: Incidences of pathologic uterine artery Doppler rate, cesarean section rate, 5-min Apgar score < 7, neonatal intensive care unit (NICU) admission and perinatal mortality were significantly higher in the EO-FGR group (p < .001). There was a decrease in Mod-MPI with gestational age in the normal (Pearson's r = 0.401, p < .001), and growth-restricted fetuses (Pearson's r = 0.248, p = .034). Mean Mod-MPI values were significantly higher in both EO- and LO-FGR group than gestation-matched controls (p < .001). There was no significant correlation between Mod-MPI values and perinatal deaths (Pearson's r = 0.004, p = .987) and 5-min Apgar score < 7 (Pearson's r = 0.391, p = .088) in the EO-FGR fetuses. There was a significant negative correlation between Mod-MPI values and cerebroplacental ratio (CPR) values (Pearson's r = -0.288, p = .041); however no significant correlation between Mod-MPI values and 5-min Apgar score< 7, and fetal distress during labor (Pearson's r = 0.149, p = 0.297) in the LO-FGR fetuses was noted. Conclusion: EO and LO-FGR fetuses have significantly higher Mod-MPI values, demonstrating prenatal cardiac dysfunction. Evaluating Mod-MPI is not so effective in predicting poor perinatal outcome in both EO and LO-FGR fetuses.