Pseudocysts of the pancreas are the commonest form of cystic lesions that often develop in patients of chronic pancreatitis and less commonly, in patients of acute pancreatitis. However, neoplastic cysts are not as common as pseudocysts and only 15% of the pancreatic cysts are neoplastic, benign, or malignant[1]. Pancreatic cystic neoplasms can present as pseudo pancreatic cysts. The differentiation amongst the two is vital as principles of management of both the diseases are different.We present a rare case of a patient being misdiagnosed as pseuo pancreatic cyst but later on found to be a case of mucinous cystadenocarcinoma of body and tail.