Abstract. This paper proposes a self-organizing hierarchical particle swarm optimization (SOH-PSO) algorithm for solving economic dispatch with multiple fuels (EDMF) and valve point effects. The PSO algorithm is simulating the behavior of birds or fish to find food. Each individual changes in velocity and position based on its experience improvement of itself and experience of both swarm. The PSO algorithm has been applied to solve many economic dispatch problems in power systems. In the new improved method, the conventional PSO algorithm is used with the variance coefficients to speed up the convergence to the global solution in a fast manner regardless of the shape of the cost function. The proposed SOH-PSO has been tested on various systems and the obtained numerical results have shown that the SOH-PSO method is more efficient and faster than many other methods reported in the literature for finding the optimal solution of EDMF. Therefore, the proposed SOH-PSO method can be a promising method for solving the practical EDMF problems.