Supernumerary teeth are reported to occur in both primary and permanent dentitions, but their exact aetiology remains unclear. To date, there have been no documented reports of supernumerary teeth formation subsequent to traumatic dental injuries (TDIs) to the primary incisors. This case report illustrates such an unusual consequence where a supernumerary tooth developed subsequent to a subluxation injury to teeth 51 and 61 in a 4-year-old Caucasian girl. This emphasizes the importance of reviewing TDIs, as well as providing parents with sufficient information about possible sequelae at the time of trauma. Nevertheless, it also provides an excellent basis for future investigations, which are essential to establish this correlation and to prove causation.