Objectives: Malignant pleural effusion (MPE) is a common and debilitating clinical manifestation in the patients with metastatic and advanced stage of neoplastic disease. This prospective study was designed in an endeavor to scrutinize various biochemical parameters like pH, glucose, protein, albumin and adenosine deaminase (ADA) in an array of malignant pleural effusions. Methods: Patients with malignant pleural effusions were diagnosed by thoracentesis through cytology and pleural needle biopsy. Results: The low pH levels in pleural fluid were associated with significantly lower pleural fluid glucose levels in malignant pleural effusions. The pleural fluid protein levels were ? 3.1 g/dL and the albumin levels ranged from 1.1 to 3.9 g/dL in malignant (exudative) pleural effusions. Furthermore, the pleural fluid ADA values (? 40 U/L) seldom exceeded the diagnostic cut-off for tuberculosis in either primary/metastatic malignant pleural effusions. Combination of these biochemical parameters considered in the present study can be used to deduce malignant pleural effusions, even if they are cytologically negative and should be subjected for repeated cytology or advanced work up for malignant primary. Conclusion: We could adjudicate that this study adds value to the existing knowledge of the pulmonologists about the biochemical profile of malignant pleural effusions, thereby ensuing in a more appropriate treatment intervention according to the histological variants of malignancy.