Diffuse large B-cell lymphoma of the frontal sinus is a very rare malignant tumor with atypical clinical manifestations. It usually involves the orbital and ethmoid sinuses and causes vision loss, visual field damage, and nasal obstruction as the first symptoms. Herein, we report the diagnosis and treatment of a patient with diffuse large B-cell lymphoma of the frontal sinus, introduce imaging features of the disease, and discuss the differential diagnosis and treatment of the disease.