The efficacy of endoscopic treatment in primary sclerosing cholangitis has not been clearly established. This report presents endoscopic intervention in 53 consecutive patients with this disorder. Pertinent data were abstracted from the GI-TRAC database, medical records, and cholangiograms, and clinical follow-up was obtained by telephone interview of the subjects. Assessed treatment outcomes were clinical symptom, liver function test, and cholangiographic appearance. Between 1986 and 1993, 85 patients with primary sclerosing cholangitis underwent successful ERCP, of which 36 men and 17 women underwent 100 therapeutic endoscopic procedures. Forty-three of 50 dilations, 37 of 38 stentings, 8 of 8 nasobiliary tube placements, and 11 of 17 stone extractions were technically successful. These treatments were complicated by cholangitis or pancreatitis in 15 patients. Clinical follow-up was obtained in 50 of 53 patients who had undergone 85 procedures (median follow-up of 31 months): 28 patients felt better, 21 felt the same, and 1 felt worse. Liver function tests obtained within 3 months of the endoscopic treatment were significantly improved compared with pretreatment values (P < .001). Cholangiograms showed improvement in 36% of the patients, no change in 51%, and the effect of therapy could not be assessed in 13%. Overall, 41 of 53 patients (77%) had improvements of their clinical symptoms, liver function tests, or cholangiograms.