Abstract This paper presents a review of the current state of the art solutions to the problem of wind farm optimal design. The aim of this work is to present the problem by identifying the most relevant issues involved in the design of a wind farm, as well as to discuss the optimization techniques and wind farm models used in the published literature. An appropriate wind turbine layout is vital in order to obtain adequate performance in relation to the exploitation and operation of the plant during its lifespan. There are several factors that influence wind farm design, chief among them are the calculation of the overall energy yield by the wind farm and the initial investment. The energy produced depends on the local wind conditions and the interference caused by wind turbines nearby. The investment is mainly related to wind turbine acquisition, civil works and electrical infrastructure. However, these are not the only items that influence the design of a wind farm since economic indicators, environmental issues, local regulations, or the presence of wind farms should also be taken into account when deciding the design of the wind farm. Even in the case of the most simplified objective function (maximizing the annual energy produced) the optimization problem cannot be solved by classical optimization techniques. To cope with this problem, most authors have used meta-heuristics techniques which have proved to be efficient when searching for the optimal solution to this problem. The purpose of this paper is to review previous work by offering a clear outline of the latest advances, as well as to highlight the main aspects which need to be taken into account when tackling the wind farm design problem. In addition, in a conclusion of the review, future needs have been identified.