Of the pleural adenocarcinomas, 96.1% were positive for thyroid transcription factor-1, 94.1% for Surfactant Protein A, 35.3% for Surfactant Protein A, 2% for calretinin and for mesothelioma Ab-1, 0% for desmin. Conclusion: After analyzing the results, it is concluded that Cytokeratin, Thyroid Transcription Factor-1, Surfactant Protein A, Desmin, Mesothelioma Ab-1 and Calretinin are the well immunohistochemical markers for differentiating malignant pleural mesothelioma from pleural adenocarcinoma.