Seismic tomography is applied in the exploration of the subsurface of a prehistoric site for remains of human structures.Prehistoric sites are important foraccessing information on human history in times of limited written evidence. Knowledge of the subsurface character and pattern of possible structural remains can be of great help in excavation design and assessment. A case history of the application of seismic tomography at Palamari prehistoric site, Skyros Island, Aegean Sea,Greece, is presented. Energysourcesandrecordersareplacedonthegroundsurface.Traveltime dataareanalysedandprocessed with three-dimensional tomographic inversion software. Seismic velocity images of the subsurface are constructed. Modelling of the subsurface is used to improve the interpretation and assist in the evaluation of the significance and reliability of the results.Velocity variations are known to correlate well with the lithological character of the earth materials, thus providing important structural andlithologicalinformationofthe subsurface.Theresultsshowagood correlation, intermsoflocation, geometry and dimensions, with expected and excavated real dimensions and pattern of the foundation and near-surface structure