Abstract: Kawasaki Disease (KD) is an acute systemic vasculitis, predominately affecting children under 5 years of age. KD is characterized by fever, bilateral non-exudative conjunctivitis, erythema of lip and oral mucosa, cervical lymphadenopathy, changes in the extremities and polymorphous exanthema. The major sequelae of KD are related to the cardiovascular system, especially the coronary arteries. This study analyzed the anatomical-pathological substrata of oral mucositis in 1 baby affected by KD.