Diagnostic and therapeutic interventional radiology techniques in 41 patients with complications of pancreatic inflammatory disease (noninfected pseudocyst, infected pseudocyst, phlegmon, abscess, hemorrhagic pancreatitis) are described. Computed tomography or ultrasound-guided aspiration or percutaneous pancreatic ductography enabled specific diagnoses in 43 of 45 patients (96%). In almost half the patients, diagnostic aspiration with 22-gauge needles was unsuccessful due to viscous contents or firm cavity walls. Single-step needle aspiration of noninfected pseudocysts was successful in only three of ten patients (30%). Catheter drainage cured six of seven noninfected pseudocysts (85.7%) and seven of nine infected pseudocysts (77.7%). Pancreatic phlegmons were aspirated in five patients to exclude secondary infection and help determine the need for surgery. Pancreatic abscesses were drained successfully in nine of 13 patients (69.2%); temporizing benefit was achieved in the other four who eventually underwent surgery in improved condition. Early diagnosis of the complications of pancreatitis may be established almost uniformly, and at least 70% of patients with infected or noninfected pseudocysts and pancreatic abscesses may be cured by nonoperative drainage.