OBJECTIVE: 1. To present the etiology, diagnostics and treatment of pleural effusion, 2. Demonstrate the role of nurses in the care of patients with pleural effusion. INTRODUCTION: The paper deals with the problem of pleural effusion. The subject of study was chosen because pleural effusion is usually a consequence and form of other underlying diseases, and therefore therapeutic approaches to pleural effusion can vary significantly, and timely and accurate diagnosis greatly affects the course of treatment and quality of life of patients with pleural effusion. In the pleural space, smaller amounts of fluid are normally present as a result of hydrostatic and colloid-osmotic pressure, which are always in equilibrium in the normal state. A pleural effusion is a buildup of fluid that is present in the abnormal volume in the pleural space, and is usually the result of excess fluid and / or decreased absorption of the lymph. Pleural effusions are divided into: transudate, exudate, chylosic and hiliform. They can also be complicated and uncomplicated. The aims of the study are to investigate the causes and mechanisms of the occurrence of pleural effusions, to classify pleural effusions and to define steps in the diagnosis and therapeutic treatment of patients with pleural effusion. DISCUSSION: The role of the nurse is of great importance in the care of patients with pleural effusion. From patient admission, treatment, health care, vital function control, recognition of pleural effusion symptoms, and together with physicians care for patients with pleural effusion. CONCLUSION: A high level of knowledge and expertise in symptom recognition, treatment and prevention of pleural effusion is required. Nursing interventions are provided at all levels of health care.