Introduction The COVID-19 pandemic was a stressful period. Lockdowns may have added to parental difficulty leading to an increase in violence. This study aimed to compare the monthly incidence of high suspicion of child physical abuse before and during the COVID-19 pandemic. Material We have retrospectively reviewed imaging examinations of children having a skeletal X-ray examination in six university hospitals with high suspicion of abusive head traumatism (AHT), inflicted skeletal trauma (IST) and unexplained skin lesions (USL) between March 2020 and June 2021 and compared with the similar period from 2018 to 2019. The monthly incidence of the different physical maltreatment was analyzed using a QuasiPoisson regression model. Results We included 178 children (n = 127 boys, 71.3 %), 110 during the pandemic period, median age 5 months. AHT was diagnosed in 91 children, 55 had inflicted skeletal trauma (IST) and 46 had unexplained skin lesions (USL). Among the 91 patients with AHT, 86 had a subdural hematoma (95.6 %) and 40 had bridging veins thrombosis (44 %). The ophthalmological examination performed on 89 children (97.9 %) revealed retinal hemorrhages in 57 children (89.8 %). The incidence of AHT doubled during the months of COVID-19 lockdowns (rate ratio = 2; 95 % CI [1.1; 3.6], p = 0.03). No difference in monthly incidence was observed for IST and USL groups. Conclusion A significant increase in AHT was observed during the months with lockdowns and curfews during the COVID-19 pandemic. This highlights the need for developing a national strategy to prevent physical abuse in children in this context.