['Pancreatic pseudocysts are a major complication of chronic and acute pancreatitis and often require endoscopic intervention. Endoscopic single-step and multi-step transmural drainage techniques have been reported in the literature. The aim of this study was to evaluate and compare technical results and clinical outcome rates of the single-step versus multi-step endoscopic ultrasonography (EUS)-guided endoscopic transmural drainage in patients with symptomatic pancreatic pseudocysts of >4 cm size.', 'Retrospective study at an academic tertiary referral center.', 'A total of 38 consecutive patients comprising 42 interventions were studied: 16 patients with pancreatic pseudocysts (18 interventions) had undergone single-step EUS-guided transmural cystostome drainage between 2007 and 2010. Results were compared with a cohort of 22 patients who had submitted to multi-step EUS-guided transmural drainage of pancreatic pseudocysts in 24 cases between 2005 and 2007.', 'The technical success rate for using the single-step procedure was 94% compared with multi-step procedure with 83% (n.s.). Primary clinical success rate was 88% for single-step drainage and 90% for the multi-step approach (n.s.). The mean procedure time was 36 ± 9 min in the single-step group compared with 62 ± 12 min for the multi-step access (p < 0.001).'] Is single-step versus multi-step transmural drainage of pancreatic pseudocysts : the use of cystostome effective and timesaving?