['To evaluate the efficacy of multimodality therapy in patients with esthesioneuroblastoma (ENB).', 'From 01/1979 through 08/2001, 47 patients with ENB (20 men, 27 women, age 5-81 years), were registered from 18 oncologic centers. There were 14 tumors stage B and 33 stage C according to the Kadish classification. Initial treatment included surgery alone in seven patients, radiotherapy (RT) with or without chemotherapy (CTX) in twelve, surgery plus postoperative RT in 15, and multimodality therapy (surgery plus pre- or postoperative CTX plus postoperative RT) in 13.', 'The 5-year overall survival (OS) for the whole group was 64 +/- 8% and the 5-year event-free survival (EFS) 50 +/- 8%. Patients with multimodality treatment had a significantly better 5-year EFS (74 +/- 13%) compared to the other patients (41 +/- 9%; p = 0.05), while the 5-year OS was not significantly different between the treatment groups (p = 0.39). For patients with Kadish stage C, multimodality therapy (n = 11) resulted in superior 5-year EFS (72 +/- 14% vs 17 +/- 9%; p = 0.01). These patients tended to have an improved OS (69 +/- 15% vs 47 +/- 12%; p = 0.19) compared to the other treatment groups. None of the patients with multimodality treatment had a metastatic relapse.'] Does multimodality therapy including radiotherapy and chemotherapy improve event-free survival in stage C esthesioneuroblastoma?