There are few data regarding the characteristics of premature ventricular contractions (PVCs) in healthy children and their impact on left ventricular (LV) function. The purpose of this study was to assess the prevalence of LV systolic dysfunction in children with frequent PVCs (≥10%) and determine whether it is associated with PVC characteristics (e.g., proportion, coupling interval, width, and/or morphology). We conducted a single-center cohort study of children with structurally normal hearts and PVC burden ≥10% by 24-hour Holter monitoring performed between 2008 and 2012. Clinical, arrhythmic, and echocardiographic data were reviewed at baseline and during follow-up. A total of 47 children (22 female [47%], mean age 8.2 ± 6.5 years) had a mean PVC burden of 20.9 ± 11.9% at baseline. The PVC coupling interval averaged 430 ± 110 ms, with a PVC width of 118 ± 27 ms. PVCs were monomorphic in 44 patients (94%). Although no patient had severe cardiomyopathy, 7 (15%) had reduced shortening fraction (Z-score <-2). A strong association was observed between PVC coupling interval and LV shortening fraction Z-score <-2.0 (area under the curve 0.95 ± 0.03, P <.001). A cutoff value <365 ms yielded the greatest discriminatory ability (Youden J-statistic 0.72, sensitivity 85.7%, specificity 86.5%). PVC proportion, width, and morphology were not significantly associated with LV shortening fraction. During 4.0 ± 2.8 years of follow-up, the PVC burden decreased from a median of 18% to 1.5% (P<.001). PVCs in children with structurally normal hearts are associated with a relatively benign course, with spontaneous resolution in most children. Mild LV systolic dysfunction, observed in 15%, is strongly correlated with a shorter coupling interval (<365 ms).