Diastolic dysfunction has been shown to occur earlier than systolic dysfunction in iron overload states in adult patients with sickle cell disease (SCD). Tissue Doppler imaging (TDI)-derived E/E' has emerged as a noninvasive marker of diastolic function. We sought to determine diastolic function in children with SCD and study its relation with iron overload. A retrospective review of medical records of 225 pediatric patients with SCD who received an echocardiogram between January 2008 and December 2012 was performed. Echocardiographic measures including Mmode, spectral Doppler, and TDI-derived E/E' were compared with previously published data in healthy children. The left ventricular end-diastolic and end-systolic dimensions were significantly higher in SCD (P<0.0001) and the shortening fraction was similar (P=0.66). E/E0 ratio was significantly higher in SCD at the mitral annulus, septum, and tricuspid annulus. In 54% of subjects, the septal E/E0 was >8, indicating elevated left ventricular filling pressure. However, there was no significant correlation between ferritin level and E/E' ratios. Pediatric patients with SCD have a high prevalence of elevated estimated left ventricular filling pressure, but this does not correlate with ferritin levels.