Background With the development of novel devices, medical thoracoscopy (MT) nowadays is very commonly used among pulmonology specialists. It is considered the gold standard not only in the diagnosis but also in the treatment of pleural diseases as it helps in solving many diagnostic and therapeutic pleural problems. Aim To categorize pleural diseases according to their appearance and pattern of distribution through inspection of pleura by thoracoscopy and to explore the ability of thoracoscopic picture to predict the etiology in patients with pleural effusions. Patients and methods This observational prospective study was conducted at Chest Department, Zagazig University Hospitals, during the period from January 2017 to January 2019. It included 90 consecutive patients with undiagnosed exudative pleural effusion who were indicated for MT to reach definitive final diagnosis. Results A total of 90 patients, with a mean age of 50.5±16.08 years, underwent MT. Overall, 45 (50%) patients presented with right-sided pleural effusion, 35 (38.8%) patients with left-sided pleural effusion, and 10 (11.1%) patients with bilateral pleural effusion. Moreover, 37 (41.1%) patients showed moderate pleural effusion, whereas 53 (58.8%) patients presented with massive effusion. Malignant pleural involvement was diagnosed in 52 (57.8%) patients. Regarding thoracoscopic pictures, 43 (47.8%) patients showed pleural nodules [32 (35.6%) patients had parietal pleural nodules, whereas 11 (12.2%) patients had visceral pleural nodules]. Pleural thickening was evident in 21 (23.3%) patients, pleural adhesions in 15 (16.7%) patients, pleural masses in seven (7.8%) patients, pleural plaques in two (2.2%) patients, and hyperemic pleural surface appeared in 26 (28.9%) patients. Conclusion The main role of MT is in the invasive management of otherwise undetermined pleural effusions (both diagnosis and local treatment). It has the ability to drain the thoracic cavity completely, can also break up pleural fluid loculations, and can visualize the entire aspect of the pleural space. Pattern of pleural involvement could be helpful in suggesting the possible pleural disease.