Amelogenin, a protein involved in the formation of enamel occurs as two isoforms, AMEL X and AMEL Y, which are encoded on the X and Y chromosome respectively. Isoform-specific peptides can be used for the determination of the chromosomal sex in ancient teeth. This strategy was used here to determine the chromosomal sex of Māori-era individuals, ca. 250-170 cal BP, in the context of a study investigating the diet, childhood residency and chromosomal sex from the isotope and peptide analyses of kōiwi tangata (human remains).