Background: Malignant mesothelioma is a rare but fatal disease that arises from the epithelial lining of the pleura, peritoneum, pericardium and tunica vaginalis. Malignant pleural mesothelioma (MPM) is the most common form, accounting for 80-90% of malignant mesotheliomas Aim of the work: was to identify the value of CT in diagnosing malignant pleural mesothelioma and applying the AJCC and the IMIG staging system for MPM. At the time to identify the limitations of CT if any. Patient and methods: This prospective study included a total of 20 patients with CT findings suggestive of malignant pleural mesothelioma, diagnosed at Radiology Department, Damanhur Oncology Center. All patients had undergone multislice CT chest with intravenous contrast for detection and staging of the tumor. This study was conducted between March 2018 and December 2018. The data collected were tabulated and analyzed statistically. Results: CT study of the chest for cases of MPM was able to evaluate and diagnose the disease, with most of the important staging items being easily seen on CT yet this study also showed the limitations of CT in the staging MPM since CT alone was not able to prove the involvement of the chest wall, diaphragmatic muscle and trans diaphragmatic extension. Conclusions: Chest CT alone is often sufficient for disease staging and treatment planning. Typical CT findings that suggest MPM include unilateral pleural effusion with nodular irregular pleural thickening which can be discrete or diffuse with or without inter lobar fissure thickening and nodal metastasis.