Needle knife papillotomy (NKP) was used to achieve diagnostic endoscopic cholangiography in 39 patients and endoscopic sphincterotomy in 24 patients when conventional endoscopic methods had failed. These patients represent 2.2% (cholangiography) and 4.2% (sphincterotomy) of the total number of patients undergoing these procedures during the same period. Cholangiography was achieved in 37 of 39 patients and sphincterotomy was successfully accomplished in all 24 patients with the assistance of NKP. Complication rates of 2.5% for cholangiography and 12% for sphincterotomy are higher than our own rates for non-NKP-assisted procedures, but the clinical benefits obtained were considered to outweigh these increases or the risks of alternative procedures. NKP is an effective endoscopic tool, allowing endoscopic sphincterotomy to be performed when conventional techniques fail. In addition, in carefully selected cases, NKP is helpful in allowing diagnostic cholangiography when other endoscopic methods fail.