The effectiveness of control strategies in achieving the objectives of a performance-based-design is well accepted in the earthquake engineering community. Consequently, various methods have been proposed for optimal design of dampers and their distribution along the building height. Most of the formulated methods concentrate mainly on reducing the responses with no explicit consideration of their long-term economic impact. In this study, an optimization problem is formulated for optimally distributing viscous dampers by minimizing the initial cost subject to a constraint on the total expected seismic loss. An intensity based assessment is used for the computation of the total expected loss. A generic Sequential Linear Programming procedure is employed to solve the formulated optimization problem. Implementation scheme of the optimization procedure is outlined in detail. The efficacy of the proposed procedure is illustrated by applying it on a four story reinforced concrete frame. It has been shown that the optimization procedure results in the optimal quantity and distribution of viscous dampers along the height of the case study building.