Dooring events in which a moving vulnerable road user, such as a cyclist, impacts an open vehicle door represent a well-known collision type, though little is known about the associated injury risk. This study leveraged 10 years of data from the National Electronic Injury Surveillance System to characterise cyclist injuries associated with dooring events. After filtering out cases which did not include explicit mention of a collision with an open vehicle door using the narrative, 644 cases were identified, representative of 17,156 injured persons presenting to emergency departments in the United States. Narratives were reviewed to determine helmet usage, cyclist fall status, and additional context for the coded injury diagnosis and body region. Superficial injuries were observed in nearly half of all events (48%), and fractures were noted in approximately 13% of all cases. Non-objective injury outcomes (complaints of pain only) occurred in 17.3% of events. While most events resulted in superficial injuries and/or did not require hospital admission, some serious or greater injuries were observed, either due to direct contact with the open vehicle door or subsequent contact with the ground or surrounding environment. This represents the first national estimate and investigation of dooring injuries in the United States.