The hybrid nature of Public Owned Enterprises (POEs) presents opportunities, difficulties, and challenges. This paper focuses on the implementation of transparency, anti-corruption and accountability in POE in Spain. Spain is one of the European countries with lower importance of public owned enterprises. However, the privatisation process has been intense in Spain and it is accompanied by a parallel process of development of public enterprises at the regional and local levels. The analysis shows the need to improve the compliance of anti-corruption, transparency, and accountability measures by public enterprises in Spain. The mere existence of laws on this field is not enough to prevent corruption. The main risks and problems identified concern the political influence, the lack of professional management, the contracting procedures, and the confusion between the public and private sphere.