RESUMEN
This is the first report on ERCP cases in Costa Rica, based on 264 cases. 58 per cent of the studies were made on women. The most frequent reference diagnostic were papilitis (19 per cent), extrahepatic cholastasis (16.6 per cent), choledocolithiasis (8.7 per cent) and jaundice (7.2 per cent). The papilla was seen in 96 per cent of the studies and cannulated in 89 per cent of the cases. The common bile duct was dilated in 62.4 per cent of the cases (70 per cent of these cases measured between 10 and 20 mm). The pancreatic duct was seen in 40 per cent of the studies. 11 cases of caranorna af the papilla were found. The final diagnostics were chronic papilitis (50.4 per cent), chdcdoodiffiiasis (16 per cent) and noncondusive study (10 per cent).