A reconnaissance seismic refraction survey was carried out in the South Australian portion of the Eucla Basin, to determine the general shape of the basin and to assess the feasibility of using seismic methods in the area. Some of the refractors recorded were correlated with lithological units encountered in some of the old water bores in the area. The highest speed refractor recorded and interpreted as granitic or metamorphic basement defines a trough containing up to 6000 feet thickness of lower velocity formations. The axis of the trough is in a NW direction through Nullarbor Homestead, and plunges to the SE. Doubt exists as to the exact interpretation of the intermediate refractors, owing to the lack of geological knowledge at the depths indicated by the refractors. Fair seismic refraction results can be obtained in the area, after allowing for slow shothole drilling rate and large explosive consumption.