BACKGROUND Pancreatic pseudocysts (PP) following acute pancreatitis have traditionally been approached by observation to allow cyst maturation. However, recent evidence suggests a selective approach toward management is indicated. METHODS We retrospectively reviewed the presentation, operative management, and outcome of patients developing PP following acute pancreatitis since 1988. PP related to chronic pancreatitis were excluded. RESULTS Twenty-seven patients were identified, 17 with giant PP (> 10 cm) and 10 with PP less than 10 cm. Groups were not different with respect to age and etiology of pancreatitis, predominantly biliary. Patients with giant PP had a significantly greater number of Ranson criteria at presentation and underwent drainage procedures earlier following their initial presentation. With respect to giant PP, 7 patients underwent internal drainage all via cystogastrostomy with 5 complications. Nine of 10 patients underwent urgent operation via external drainage. There were 3 pancreatic fistulas in this group. The morbidity and mortality rates for giant PP were 65% and 18% respectively. With respect to smaller PP, 8 underwent internal drainage with 1 death (mortality rate 10%). External drainage was performed in 2 patients with 1 pancreatic fistula (morbidity 10%). CONCLUSIONS Patients with PP and a high Ranson score following acute pancreatitis are at significant risk for giant PP formation. Expectant management of giant PP is associated with higher morbidity and mortality than small PP suggesting that earlier external drainage, before clinical deterioration, may be beneficial. To be accurate, comparisons of outcomes for various treatment modalities must take into consideration PP size.