Summary: Pleural effusion is a universal diagnostic problem, especially in the group of hospitalized patients. Thoracentesis should be performed to assess the exudative or transudative nature of the effusion. Computed tomography, pleural biopsy or thoracoscopy are performed to expand the diagnostic options. In individual cases, talc pleurodesis is performed, or indwelling pleural catheters are inserted into the pleural cavity. The latter method is particularly recommended because, being uncomplicated, it can be performed by non-surgeons or specialized pulmonologists.