A 51 year-old female presented with a recurrent vulvar mass. Excision biopsy showed an incompletely excised malignant lymphoma. The Working Formulation classification was diffuse mixed large and small cell non-Hodgkin's lymphoma. Under the recently proposed classification system known as the Revised European-American Lymphoma (REAL) classification it was a diffuse large B-cell lymphoma. Primary vulvar lymphomas are rare and it was important to exclude systemic disease and an underlying immunodeficiency disorder. Possible pathogenesis, natural history and pathology are discussed. Chemotherapy and radiotherapy are the principal modalities of therapy at most sites and surgery should be limited to diagnostic purposes.