In this work, strontium stable isotopes and trace elements analysis were used for assessment of migration phenomena in five human skeletons, found in 2017 in Tepe Silveh excavation in Piranshahr, northwestern Iran. On the basis of the associated findings, these skeletons belong more likely to the Millde Islamic Periods (Seljuk era). Due to the proximity of the site to the Iran, Iraq and Turkey boundaries, this study, as the first investigation about the likely migration of the ancient occupants of this region, is of a high importance. The elemental content of both tooth and bone samples of the skeletons was analyzed by ICP-MS technique and the strontium isotopes ratio (87Sr/86Sr) and trace elements ratio (Ba/Ca and Sr/Ca) were obtained to address whether these skeletons are local or non-local. The results of strontium isotope analysis (87Sr/86Sr) showed that all the samples could be considered as non-local, where the isotopic ratios were out of local range (local mean ± 2SD). Moreover, the results of trace elements analysis proved the strontium isotope results, where the difference between the ratio of Ba/Ca and Sr/Ca in tooth enamel and bone shows the possible non-local nature of the skeletons, or in other words, it could be said surely that these people have spent their childhood in different places.