Pancreatitis may be acute or chronic, mild or severe. In patients with acute pancreatitis the optimal imaging test is dynamic intravenous and oral contrast enhanced computed tomography (CECT). Serial CECTs are useful to monitor disease progression and to assess intraabdominal complications in patients with severe acute pancreatitis. CECT is helpful in planning the approach (endoscopic transmural versus percutaneous) for pancreatic drainage. Computed tomography or ultrasound-guided aspiration of pancreatic collections is safe, sensitive, and specific and has become a routine procedure used to screen for infected necrosis. When pancreatic drainage is contemplated, magnetic resonance imaging is useful for identifying residual necrotic debris within the collection. Patients with mild acute pancreatitis usually require no cross-sectional imaging study other than ultrasound screening for gallstones, if gallstone pancreatitis is suspected clinically. In patients with chronic pancreatitis, screening for complications such as superimposed acute pancreatitis or development of pancreatic pseudocysts may be performed with CECT or ultrasound.