This article presents a new evolutionary optimization approach called gray wolf optimizer (GWO), which is based on gray wolf behavior for an optimal generating operation strategy. The GWO algorithm does not require any information about the gradient of the objective function, when searching for an optimal solution. The concept of the GWO algorithm, it seems a powerful and reliable optimization algorithm is applied to dynamic economic dispatch (DED) problem considering wind power. Many practical constraints of generators such as valve-point effects, ramp rate limits, and transmission losses are considered. The proposed algorithm is implemented and tested on two test systems that have 5-unit and 10-unit generators. The results confirm the potential and effectiveness of the proposed algorithm compared to various other methods are available in the literature. The results are very encouraging and prove that the GWO algorithm is a very effective optimization technique for solving various DED problems.