In organic farming, plant health is maintained primarily through preventive management practices. Nevertheless, there are crops and situations where such measures alone do not provide sufficient protection, and direct plant protection is therefore necessary. This chapter focuses on the substances which may be used for plant protection, as well as underlines the importance of indirect plant protection measures for organic farming systems. The chapter describes current practices in organic plant protection, identifies currently authorised materials and discusses the process of authorisation of materials in the European Union. It finally examines efforts to find replacements for copper fungicides and looks ahead to future trends in this area of research.