The bacteriological changes appearing on transport of legs of beef, pork carcases and parts of cattle and pigs were studied. Meat from three slaughter-houses was examined. Of the meat of each slaughter-house, specimens transported over a short distance, over a long distance or by the butcher's own vehicle were studied. The transported meat was found to be contaminated by bacteria which had developed on (other) meat. The hygienic condition of the meat-van obviously is a factor in the transfer of bacteria to legs and carcases; this was not observed where the parts were concerned. The effect of bacterial contamination was that the decrease in stability was most marked in meat showing low bacterial counts. The season during which the meat was transported and the temperature reached during transport were not found to have any appreciable effect on the increase in bacterial counts. Nor were any marked differences observed between slaughter-houses or the various transports to butcher's shops. On the other hand, there was a relatively marked increase in bacterial counts on a particular transport route on which the meat had to travel for periods varying from five to six hours.