The Atlanta classification of acute pancreatitis was introduced in 1992 and divides patients into mild and severe groups based on clinical and biochemical criteria. Recently, the terminology and classification scheme proposed at the initial Atlanta Symposium have been reviewed and a new consensus statement has been proposed by the Acute Pancreatitis Classification Working Group. Major changes include subdividing acute fluid collections into “acute peripancreatic fluid collection” and “acute post-necrotic pancreatic/peripancreatic fluid collection (acute necrotic collection)” based on the presence of necrotic debris. Delayed fluid collections have been similarly subdivided into “pseudocyst” and “walled of pancreatic necrosis”. Appropriate use of the new terms describing the fluid collections is important for management decision-making in patients with acute pancreatitis. The purpose of this review article is to present an overview of complications of the acute pancreatitis with emphasis on their prognostic significance and impact on clinical management and to clarify confusing terminology for pancreatic fluid collections.