Right ventricular (RV) and atrial (RA) dilation has been clinically observed in patients after initial repair of tetralogy of Fallot (rTOF) and is associated with adverse long-term outcomes. Due to RA and left atrial (LA) interaction, we aimed to determine the effect of RA dilation on LA performance from feature tracking cardiovascular magnetic resonance (CMR) in pediatric rTOF patients. Results revealed that LA strains and strain rates were impaired in rTOF than age- and gender-matched healthy volunteers. RA volumes are negatively associated with LA strains. These findings may suggest LA diastolic dysfunction from chronic RV and RA dilations in rTOF, even at early stage after initial repair.