Background Malignant pleural effusion (MPE) arises in advanced stages of malignancies and frequently carries a poor prognosis. The most common management of the patients with refractory MPE is pleurodesis. Ultrasound is easy, bedside, cheap, and an accurate method to detect successful pleurodesis by using the pleural sliding sign due to movement of parietal pleura on visceral pleura. Aim To detect the efficacy of thoracic ultrasound (TUS) assessment in patients undergoing pleurodesis for recurrent symptomatic MPE. Patients and methods The study was carried out at the Chest Department, Zagazig University Hospital from October2016toAugust2017.Itincluded32patientswithrecurrentMPE,fourmenand 24 women. They were divided into four groups according to the method of pleurodesis (tetracycline, fluorouracil, povidone–iodine, and spontaneous pleurodesis). Chest ultrasound was done before pleurodesis and 1 month after pleurodesis for assessing the presence or absence of lung sliding sign in different areas. Results The study show that TUS can be used to detect successful or failed pleurodesis by using lung sliding sign. In the tetracycline group, 12.5% of patients showed successful pleurodesis. In the fluorouracil group, 100% of patients had successful pleurodesis. In the povidone–iodine group, 75% of patients had successful pleurodesis. In spontaneous pleurodesis 50% of patients had successful pleurodesis. Conclusion TUS is an easy and accurate method for the detection of successful pleurodesis. Fluorouracil and povidone–iodine carry better prognosis than tetracycline and spontaneous pleurodesis.