Abstract Background We proposed to analyze thoroughly the impact of the COVID-19 lockdown (CL) in changes of profiles and in trend of the domestic accidents (DAs) in children. Methods This was a single experience, cross-sectional study conducted at the emergency department (ED) of III trauma center. We enrolled children under 18 years admitted to ED with a diagnosis of DAs comparing the CL period from 10^th March 2020 to 4^th May 2020 with the same period of the previous year,10^th March 2019 to 4^th May 2019. Results In CL period, the cumulative incidence of ED visits for DAs increased from 86.88 to 272.13 per 1,000 children and the cumulative incidence of hospitalizations for DAs increased from 409.72 to 534.48 per 1,000 children. We reported in CL a decrease in the severity of ED presentation assessed by proxy measures: the level of priority ED visits reduced by 67% in CL period (OR: 0.33; 95%CI 0.22–0.48; p < 0.001); the likelihood of delayed time of presentation to ED increased by 65% in case of domestic injuries occurring in CL period (OR: 1.65; 95% CI: 1.17–2.34; p = 0.004); the odds of transfer from other hospital decreased by 78% in CL (OR: 0.15–0.33; p < 0.001). Children were more at risk of poisoning (OR:3.35–106.11; p = 0.001), of body foreign ingestion (OR: 1.83–14.39; p = 0.002) and less at risk of animal bite trauma (OR:0.05–0.35; p < 0.001). Conclusion Although the need to stay home has made a decisive breakthrough on the spread of COVID-19, the experience from this study underlines how this preventive measure has also had a downside in term of increased cumulative incidence of ED visits and of hospitalizations for DA.