The European Union (EU) aims to considerably reduce the emissions of harmful gases in the atmosphere, has resulted in drastic increase of power generation from renewable sources, especially wind. The nature of these sources is that it is difficult to predict their availability at certain moment of time. This increases the need to balance the generation side to the demand side and thus, the need for ancillary services (AS). In addition, the large integration of wind power on the power systems in EU imposes on markets and operators the unavoidability of wind power participation in the provision of these AS [1]. Most of the EU countries already have markets and other procurement methods for AS [2]. These procurement methods, however, are designed and based on conventional generation which limits or completely prevents the participation of wind power in the procurement of these services [3]. The challenge to reconsider the structure of current energy markets has been identified by the European Commission on the “Energy Roadmap 2050” [4]. This may contribute to provide an European common framework for the balancing markets (which is one form of a manually operated frequency control), allowing participation of wind power as well as simplified cross-border interaction. In addition, the participation in providing AS from wind power plants have been already analysed to be beneficial for both the system and the wind power producers [5]. A promising example of wind power participation on balancing markets is already happening to some extent in Denmark [6] and in Spain 3.5 GW of wind generation capacity is about to obtain the right to participate in the balancing market [7]. Also, for easing wind power participation, AS markets must be adapted for example reducing gate closure times of the markets, which will reduce wind power production uncertainty and enable offering larger capacity. The aim of the thesis is to give the state of the art of AS for frequency support (FS), the important requirements that would encourage or discourage the participation of wind power generation in their provision and to analyse the potential economic benefits they would have from this provision.