Background: Traumatic dental injuries (TDIs) in the primary dentition are f requently seen in the oral emergency department and may affect children’s mastication, pronunciation, and aesthetic function, leading to tooth defects or loss. Also, severe TDIs may have a long-term impact on children’s mental health, emotional control, and social ability. Thus, actions taken at the place of injury are important, considering that they may affect the prevention and treatment of TDIs. Methods: This retrospective study assessed children with TDIs who were initially diagnosed in a department of oral emergency in Beijing. Descriptive analyses were performed to obtain the distribution of gender, age, visiting date and time, number and tooth position of the injured teeth, and types of tooth injury. Results: A total of 9039 children, 5643 boys (62.4%) and 3396 girls (37.6%), with an average age of 3.5 years, were assessed. The incidence of primary dental trauma was highest from May to June and from September to October. The average number of daily visits on holidays was 4.65 ± 2.81 per day, and that on working days was 3.88 ± 2.42 per day (p < 0.05). The positions of traumatic teeth on both sides were approximately symmetrical, and maxillary central incisors were the most affected. Most patients (50.8% of cases) had only one traumatic tooth vs. 49.2% with two or more teeth injuries. In the injuries to the periodontal tissues, the incidence rates of subluxation and concussion were higher in the kindergarten child group (3–5 yr) and schoolchild group (≥6 yr) than in the baby group (0–2 yr) (p < 0.05). The incidence rates of avulsion and luxation in the schoolchild group were the highest, while the incidence rates of intrusive luxation in the baby group were higher than in other groups (p < 0.05). For injuries to dental hard tissue, incidence rates of complex crown-root fracture and complex crown fracture in the baby group were the highest. Conclusions: TDIs in primary dentition were most likely to occur on holidays and in warm seasons. Boys and children in the kindergarten group resulted as high-risk populations. Maxillary central incisors were the most affected. Different TDI patterns with high incidence varied in different age groups. Families, schools and kindergartens should strengthen the protection against dental trauma. Also, clinicians should be updated on treatment guidelines for TDIs in primary dentition.