Western Iran is a semi-arid region which suffers from periodic water shortages. To address water needs, a number of sites that may be suitable for the construction of storage dams have been identified. This paper highlights the geological-geomechanical characterization of the rock masses exposed in the dam abutments and foundation area at the Khorram-Roud Dam in Hamadan, Western Iran. A comprehensive engineering geology and rock mechanics study was executed at the dam site. Different rock mass classification systems including RMR, Q, RQD, GSI, RMi and DMR were applied to characterize and provide a basis for estimating deformation and strength properties of the rock masses for preliminary design calculations. Based on results from this study, a set of geotechnical suggestions were proposed for a further more detailed investigation of potential stability problems, as well as a program for impermeation and consolidation grouting. In conclusion, the studied dam site has been proposed as an appropriate site for construction of a rock-fill dam.