Primary malignant laryngeal lymphoma is rare. In this case, diffuse wall thickening of the vocal cord and infraglottic larynx was seen on initial CT scan. After chemotherapy, follow-up CT neck scans showed a marked decrease of diffuse wall thickening of the vocal cord and infraglottic larynx ; diffuse laryngeal wall thickening is, however, a nonspecific finding which can be seen in other disease processes. If clinical evidence of infection and inflammation or remarkable change after antibiotics treatment is not definite, biopsy should be performed to rule out laryngeal lymphoma.