Two black African immigrants, with no history of recent travel outside France, received a diagnosis of a malignant lymphoproliferative disorder and splenomegaly, and they subsequently underwent splenectomy. A few weeks after surgery, both patients experienced an acute episode of Plasmodium falciparum malaria, so the initial diagnosis was corrected retrospectively and changed to hyperreactive malarial splenomegaly. These cases illustrate the difficulty in distinguishing hyperreactive malarial splenomegaly from malignant lymphoproliferative disorders and therefore underline the role of the spleen in the immune system's defense against malaria.