Acute pancreatitis remains the most frequent complication of endoscopic retrograde cholangiopancreatography (ERCP), with reported incidence rates that have changed little over several decades. Patient- and procedure-related risk factors for post-ERCP pancreatitis (PEP) are well-defined. Effective measures to prevent PEP have been identified, including improvements in cannulation techniques and pancreatic stenting, as well as pharmacological intervention. Pharmacotherapy has been widely studied in the prevention of PEP, but the effect in averting PEP has been inconclusive. Although pharmacological prophylaxis is appealing, attempts to find an ideal drug are incomplete. Most available data on the efficacy of pharmacological agents for PEP prophylaxis have been obtained from patients at average risk for PEP. However, recently, a randomized prospective controlled trial of rectal nonsteroidal anti-inflammatory drugs (NSAIDs) to prevent PEP in high-risk patients was published. The results revealed that rectal indomethacin reduced the incidence of PEP significantly. Thus, rectal administration of diclofenac or indomethacin immediately before or after ERCP is used routinely to prevent PEP. However, additional studies with NSAIDs using large numbers of subjects are necessary to confirm the prophylactic effect of these drugs and to establish whether they act synergistically with other prophylactic interventions, including pancreatic stenting.