Although the spleen is frequently involved in disseminated non-Hodgkin's lymphoma (NHL), splenic presentation as the initial or only site of disease is uncommon. The true incidence of splenic lymphoma is difficult to estimate because of the variable definition of this disease, however, the diagnosis of primary lymphoma of the spleen should be limited to involvement of only the spleen and splenic hilum. Using this restricted definition, our experience suggests that the prognosis of NHL of the spleen, when pathologically staged, may have a favorable prognosis which approximates that seen with limited stage NHL at other sites. The influence of pathologic subtype on natural history and the impact of adjuvant therapy are discussed.