While isotopic and elemental analyses of prehistoric skeletons have made an important contribution to palaeodietary research over the last 10 years, certain problems in the application of these techniques only now are emerging. These problems affecting both isotopic and trace element studies, mainly are due to the peculiar interdisciplinary nature of the field, rather than to any technological barrier. With minor exceptions, techniques developed largely in other sciences have been grafted on to archaeological problems. This no longer suffices because gaps remain in the scientific grounding of these techniques that need to be addressed before more complicated archaeological questions can be resolved. While the necessary studies may seem to be of little immediate anthropological interest, they are vital if continued progress in palaeodietary research is to characterize the years ahead.