Repeat head computed tomography (RHCT) is common and routine for pediatric traumatic brain injury (TBI) patients. In mild (Glasgow Coma Scale; GCS 13–15) to moderate (GCS 9–12) TBI, recent studies have shown that RHCT without clinical deterioration does not alter management. However, the effectiveness of routine RHCT for pediatric TBI patients under 2 years has not been investigated. This study aims to investigate whether routine RHCT changes management in mild-to-moderate TBI patients under 2 years. We performed a retrospective review at the emergency department of the National Center for Child Health and Development between January 2015 and December 2019. Mild-to-moderate TBI patients under 2 years with an acute intracranial injury on initial head CT scan and receiving follow-up CT scans were included. Mechanism, severity of TBI, indication for RHCT, and their findings were listed. Study outcome was intervention based on the findings of RHCT. Intervention was defined as intubation, ICP monitor placement, or neurosurgery. We identified 50 patients who met inclusion criteria and most patients (48/50) had mild TBI. The most common mechanism was ‘fall’ (68%). Almost all RHCT was routine and the overall incidence of radiographic progression on RHCT was 12%. RHCT without clinical deterioration did not lead to intervention, although one patient with moderate TBI required intervention due to radiographic progression with clinical symptoms. Our study showed that routine RHCT without clinical deterioration for mild TBI patients under 2 years may not alter clinical management. We suggest that RHCT be considered when there is clinical deterioration such as decrease in GCS.