Urine and serum specimens from onco-haematological patients including acute myeloid leukemia (AML), acute lymphoid leukemia (ALL), multiple myeloma (MM), Hodgkin lymphoma (HL), non-Hodgkin lymphoma (NHL) and hairy cell leukemia (HCL) with confirmed febrile neutropenia were examined for presence of mip gene of L. pneumophila by PCR. This evidence concerns the gene MIP and plasma cell myeloma.