Ascites is defined as pathological fluid accumulation within the abdominal cavity.1 The word ascites is derived from the Greek word ‘askos’, which means a bag or sack.1–3 Clinically, ascites is a consequence or complication of a number of diseases, including hepatic, cardiac, and renal diseases, infection, and malignancy. Ascites usually carries an unfavorable prognosis. For example, the development of ascites in cirrhotic patients is associated with a mortality of 15% and 44% at one-year and five-year follow-up periods, respectively.4, 5 However, the prognosis largely depends on the underlying cause (i.e. the primary disease). Combined analysis of laboratory data of ascitic fluid samples and clinical and pathological data is essential for establishing a differential diagnosis. This review aims to assess critically the value of ascitic fluid analysis in the diagnosis of ascites, especially cirrhotic ascites.