Autoimmune neutropenia is a self-limiting condition characterized by the presence of granulocyte-specific autoantibodies. This case report describes a 2-year-old female who presented to the Department of Pediatric Dentistry with a history of oral ulceration, complicated by high temperature, gingival hypertrophy and gingival hemorrhage. These symptoms had precipitated an admission to a district general hospital and diagnosis of viral tonsillitis. The severity of the presentation to the Pediatric Dental Department prompted a review of recent discharge blood investigations, which revealed a neutrophil count of 0.07×109/L(1.0-8.5 ×109/L) indicating severe neutropenia. Urgent referral to Pediatric Hematology resulted in same-day admission and a diagnosis of autoimmune neutropenia was established. The patient was managed with chlorhexidine mouthwash, prophylactic antimicrobial and antifungal medication and granulocyte colony stimulating factor (G-CSF). Neutropenia may present with features exclusive to the oral cavity. Recognition of atypical presentations such as oral ulceration with associated systemic illness may assist in early diagnosis.