Expression of a number of antigens associated with small cell lung cancer (SCLC) have been proposed as a marker of malignancy and the diagnostic tool for the staging procedures and important prognostic factor. Since the bone marrow (BM) was described as a frequent site for SCLC metastases, we have decided to assess clinical importance of cancer cells detection in BM, using immunofluorescence with MAC-1, MAC-31, NSE and anti-Fucosyl-GM1 (PF3) antibodies. The group of 32 patients with SCLC was assessed using our panel of antibodies. Control group consisted of 5 patients with other malignancies (3 patients with malignant lymphoma, 1 with chronic lymphocytic leukaemia and 1 with non-SCLC). The study revealed no correlation between the expression of SCLC markers in patients BM and the cancer treatment outcome measured as a response for treatment, time to progression, and survival time, and no significant difference was found between the patients and control group.