The Soltan Dam on the river Soltan, a branch of Tine River, is located about 19 km of Mateur city in the northeast of Tunisia. The dam is now under Study and will be constructed in 2017. The Soltan Dam has been designed as an earth fill dam with homogeneous materials. The dam and its associated concrete structures are mainly founded on marl, shale and shale of Lower Miocene age, sandstone of the Hakima Formation of Middle Miocene and the Kchabta Formation of Upper Miocene age. These series are affected by high tectonic deformation due to the Post-Villafranchian compressive event. This paper discusses the site investigation for the dam.