In our study we have collected 1000 consecutive cases of oral cholecystographic opacification of the gall-bladder and common bile duct; occasionally a complimentary intra-venous cholangiography had also been carried out. In 360 cases there was disease of the gall-bladder or a faint opacification of the common bile duct was abnormal in only three cases, which is a rate of 0,47%. Therefore the fatty meal after oral cholecystography should not be done in each case but only if there is a presumptive diagnosis of pancreatic disease, if there is pancreatic calcification, or if surgery has been previously performed on the biliary tract or duodenum.