AIMS: Compared with adult patients, clinical manifestations of children's coronavirus disease-2019 (COVID-19) are generally perceived as less severe. The objective of this study was to evaluate cardiac involvement in previously healthy children with asymptomatic or mildly symptomatic severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. METHODS AND RESULTS: We analysed a cohort of 53 paediatric patients (29 males, 55%), mean age 7.5 +/- 4.7 years, who had a confirmed diagnosis of SARS-CoV-2 infection and were asymptomatic or only mildly symptomatic for COVID-19. Patients underwent standard transthoracic echocardiogram and speckle tracking echocardiographic study at least 3 months after diagnosis. Thirty-two age, sex, and body surface area comparable healthy subjects were used as control group. Left ventricular ejection fraction was within normal limits but significantly lower in the cases group compared to controls (62.4 +/- 4.1% vs. 65.2 +/- 5.5%; P = 0.012). Tricuspid annular plane systolic excursion (20.1 +/- 3 mm vs. 19.8 +/- 3.4 mm; P = 0.822) and left ventricular (LV) global longitudinal strain (-21.9 +/- 2.4% vs. -22.6 +/- 2.5%; P = 0.208) were comparable between the two groups. Regional LV strain analysis showed a significant reduction of the LV mid-wall segments strain among cases compared to controls. Furthermore, in the cases group, there were 14 subjects (26%) with a regional peak systolic strain below -16% (-2.5 Z score in our healthy cohort) in at least two segments. These subjects did not show any difference regarding symptoms or serological findings. CONCLUSION: SARS-CoV-2 infection may affect left ventricular deformation in 26% of children despite an asymptomatic or only mildly symptomatic acute illness. A follow-up is needed to verify the reversibility of these alterations and their impact on long-term outcomes.