Abnormal collection of fluid in pleural cavity isknown as pleural effusion . it is a syndrome of clinical signs andsymptoms with varying etiologies, most common being koch’s andmalignant effusion. The main focus of disease is commonly in pleura andlungs but it can be extra–pulmonary as well as systemic disorder mostcommon it is Rheumatoid Arthritis. So it is neccesary in today’s life to knowabout it. Because it can present to anybody from physician to surgeon.