One hundred and seventy-five patients with extranodal non-Hodgkin lymphoma (NHL) treated between 1974 and 1993 in the Institute of Radiology and in the Department of Haematology of 'La Sapienza' University of Rome, have been examined. The sites involved were: Waldeyer's ring 96 patients (tonsils 84, nasopharinx 12), parotid 20, orbit 16, oral cavity 16, paranasal sinus 7, mandible 7, nasal fossal 3, minor salivary glands 3, larynx 3, conjunctive 2, lacrymal glands 1, thyroid 1. One hundred and forty-three patients had high and medium grade unfavourable histology; 68 patients were in stage I, 67 in II, 23 in III and 17 in IV. Fifteen patients were treated with radiotherapy alone and 86% obtained complete remission (CR). Chemotherapy alone was used in 90 cases and 87% C.R, was achieved; when chemotherapy in association with radiotherapy was used in 70 cases 85% obtained CR. The actuarial survival rate was 79% and recurrence-free survival in those patients who achieved complete remission 87%. Surviving and relapse-free patients were analysed in relation to main prognostic factors and therapy, and patterns of recurrence are reported. From the analysis of these cases we can learn how systemic therapy combined with the general conditions of patients and histology can control the disease. A minor relapse incidence with pharmacological therapy combined with a radiotherapic loco-regional treatment was also ascertained.