Aim: Malignant pleural mesothelioma (MPM) is an aggressive tumor with poor prognosis. The study aims to examine the effect of certain clinical, laboratory, radiologic, and pathologic characteristics on survival. Patients and Methods: Sixty patients who had undergone PET/CT evaluation at initial diagnosis were included. We investigated the effect of certain clinical, laboratory, radiologic characteristics, SUVmax of the tumor, and pathological characteristics such as histological subtype, mitotic activity index (MAI), tumor necrosis, and inflammation on survival. The pathological slides of each patient were re-evaluated for MAI, presence of necrosis, and inflammation. The patients were grouped based on number of mitosis as MAI 1:≤9, MAI 2:10-19, MAI 3: >19 mitosis. Results: There were 34 male and 26 female patients with a mean age of 53.6 ΁ 10.6 years. Mean and median survival time was 14.83 ΁ 10.75 and 11.95 (min 0.43-max 48.10) months, respectively. Using univariate analysis leukocytosis (P = 0.009), rind-like pleural thickening (P = 0.037), advanced disease stage (P = 0.004), best supportive therapy alone (P = 0.004), SUVmax higher than 8 (P = 0.023), MAI higher than 1 (P = 0.033), and presence of tumor necrosis (P = 0.037) were found as poor prognostic factors. At multivariate analysis, leukocytosis (P = 0.026, HR: 2.27), advanced disease stage (P = 0.021, HR: 2.46), best supportive therapy alone (P = 0.029, HR: 5.12), and MAI higher than 1 (P = 0.01, HR: 3.01) were independently associated with survival, whereas SUVmax of the tumor failed to enter the model (P = 0.07, HR: 1.89). Conclusion: Presence of leukocytosis, advanced disease stages, supportive therapy alone, and higher MAI were found to be negative prognostic factors in patients with MPM.