BackgroundMalignant mesothelioma (MM) is an aggressive asbestos-related pleural tumor. The incidence is increasing with intensive use of asbestos in developing countries. We need an easily accessible, inexpensive, and reliable method for determining the low survival time prognosis of this tumor. The aim of our study was to investigate the viability of neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) as prognostic indicators in MM.Patients and methodsThirty-six patients with MM, whose histopathologic diagnosis and follow-up were performed by our clinic and whose complete archive data were accessible, were included in this retrospective study. The patients’ histopathologic disease types and stages, complete blood count parameters at diagnosis, and survival were recorded.ResultsEighteen of the patients with MM were male and the remaining 18 of them were female; the average follow-up period was 24.83±3.61 months. The PLR levels of the patients were statistically significant (P<0.05). The NLR and PLR area under the receiver operating characteristic curve values were 0.559 and 0.749, respectively (P=0.631 and P=0.044, respectively).ConclusionPLR was a significant prognostic indicator of MM at diagnosis on complete blood count parameters; however, NLR was not a significant prognostic indicator. A large number of prospective studies are needed to prove the reliability of the parameters.