Ascites can present a challenging diagnostic problem. Bacteria causingspontaneous bacterial peritonitis (SBP) may differ in patients with and withoutunderlying malignancies. To date, reports focusing on patients with malignanciesand ascites are less. The aim of the present study was to determine the prevalenceand causative agents of SBP in cancer and non cancer patients and the antibacterialsusceptibilities of these microorganisms. Also, to identify differences, if any, inpolymorphonuclear (PMN) cell count, interleukin (IL)-6 concentration, and differentbiochemical diagnostic parameters, we analyzed for infected and non infected ascitesin both groups.