Diffuse-type neurofibroma (DN) associated with neurofibromatosis type 1 (NF1) involving the external auditory canal (EAC) is uncommon. In DN, it is generally difficult to remove tumors without destroying normal anatomical structures because of the infiltrative and hypervascularized nature of these tumors. A 38-year-old male with NF1 visited our department because of slowly progressive hearing loss on the right side. His EAC was obstructed with a soft borderless mass around the external ear. We performed ultrasonic surgical aspirator skin to just below the surface and also into the surrounding soft tissues without clear borders. An intraoperative rapid diagnosis of neurofibroma was made. We used an ultrasonic surgical aspirator to dissect the infiltrative tumor material. This was effective and caused no damage to the adjacent epidermis or to the auricular cartilage. Subsequently, we performed an M-meatoplasty to enlarge the entrance of the EAC. His hearing acuity recovered postoperatively to the normal range. The postoperative histological diagnosis was DN. At 5.5 years postoperatively, there has been no sign of re-growth. Thus, ultrasonic surgical aspirator resection and subsequent M-meatoplasty appears to be a good surgical approach for DN involving the EAC. © The Mediterranean Society of Otology and Audiology.