Six sides of beef were chilled under widely differing conditions and the toughness measured at locations across a slice of the round. When beef carcasses were held for 6 h before chilling at 2"C, the variation in toughness across each muscle was usually small and regions of toughness varied between animals. Such variations are unimportant commercially and, for most experimental purposes, locations within each muscle may be randomised with little loss of information. The exception was the M. biceps fernoris in which the caudal region was consistently tougher than the crania1 region. When chilled to 7°C in 24 h, the cold-shortening toughness was induced to a depth of about 4cm. The resulting variation was often so large that it made the average toughness value virtually meaningless.