This paper presents a new method for the isolation and isotopic analysis of some individual amino acids from proteins. The technique and its constituent steps are discussed; then isotopic analyses of amino acids from several samples of bone collagen from the Late Roman site of Poundbury, Dorset, UK are presented.The applications of the method are discussed, as well as some advantages of this technique relative to other methods. Although developed for use with archaeological bone collagen, the technique is equally applicable to other proteinaceous materials. The use of reversed‐phase HPLC avoids problems of isotopic fractionation inherent in using ion‐exchange HPLC. Amino acids are isolated preparatively, allowing both carbon and nitrogen isotopic values to be measured on a single sample using CF‐IRMS. Since amino acids are isotopically analysed in an underivatized form (unlike GC‐C‐IRMS), the method also presents the possibility of collecting the CO2 generated during CF‐IRMS: this would allow the subsequent dating by 14C‐AMS of individual amino acids isolated from archaeological samples.