A 63-year-old female suffering from hepatitis C virus infection and manic depression was admitted with a 4-month history of hoarseness. Endoscopic examination revealed the presence of a neoplasm with a smooth surface in the left supraglottic region extending to the left false vocal cord. Based on the histological findings, together with the results of systemic evaluation, the patient was diagnosed as having a mucosa-associated lymphoid tissue (MALT) lymphoma in clinical stage IE, according to the Ann Arbor classification. After one month of follow-up, the patient presented with involvement of multiple subcutaneous regions in the left neck area, etc. Biopsies revealed the same type of lymphoma as that in the supraglottis. The disease was considered to have progressed to clinical stage IV. Six courses of R-CVP (rituximab, cyclophosphamide, vincristine and prednisolone) treatment resulted in complete remission of all lesions. Primary MALT lymphoma in the larynx is extremely rare. Since the first description by Diebold et al in 1990, only 43 cases have been reported. Among these reported cases, only 7 (16%) with progressive stages were described. The R-CVP regimen appears to be effective for the treatment of progressive primary MALT lymphoma of the larynx. Furthermore, hepatitis C virus infection is thought to be closely associated with the aggressive malignant process and subcutaneous dissemination.