We studied 30 patients with early stage malignant lymphomas involving the nasal cavity and/or paranasal sinus who were treated between 1972 to 1991 in Hokkaido University Hospital. The mean age of the patients was 60.6 yr, and the male-to-female ratio was 2.6. The predominant histologic type was diffuse large cell type (n = 23). Treatment policy differed depending on time: radiotherapy (RT) alone between 1972 and 1980 (n = 15), RT followed by modified CVP or CHOP between 1981 and 1988 (n = 10) and BACOP followed by RT between 1989 and 1991 (n = 5). Overall five-year survival was 53%. Better survival was observed in patients with B-cell type (72%), smaller mass (tumor limited to the unilateral nasal cavity or paranasal sinus) (76%), and patients who were treated with combination chemotherapy (BACOP) followed by RT (100%). Eleven patients experienced recurrence. Four of nine local recurrences were in patients with T-cell lymphoma. CNS relapse was observed in three patients with T-cell lymphoma. We conclude that T-cell lymphoma arising at the nasal cavity and/or paranasal sinus needs careful follow-up for its high frequency of local and CNS relapse. More intensive treatment such as prophylactic whole brain RT, intrathecal administration of MTX or third generation chemotherapy (e.g. MACOP-B) might improve survival in these patients.