The most common problem in earth dams is abnormal seepage or excessive leakage after the foundation of the dam. When water started to fill the reservoir in Akdegirmen dam (Afyonkarahisar. Turkey) designed as a zoned earth dam, the seepage developed at the base of the spillway and the downstream of the right bank. The leakage at this dam was investigated by using electrical resistivity and self-potential measurements. The dipole-dipole electrode array with unit electrode spacing of 10 m was used for resistivity imaging survey. An algorithm based on robust inversion technique was used to invert electrical resistivity data. The self-potential data were collected by fixed reference method and interpreted qualitatively by graphs. The investigation results revealed the distribution of strata and the leakage paths along the downstream of the right bank.