For many years, European patents have been granted for plant breeding. Nevertheless, in many cases, it is still unclear to what extent plants and their breeding methods are actually eligible for patent protection. This book aims to clarify the fundamental conditions under which plant breeding can currently be patented according to existing legal standards. In addition to the general patentability requirements, which are analyzed in relation to the specificities concerning the patentability of plant breeding, the patentability exclusion for plant varieties and essentially biological processes for the breeding of plants, as stipulated in Article 53(b) of the European Patent Convention, is discussed in detail. The discussion of existing old and new case law from the Boards of Appeal of the European Patent Office is particularly significant for the reader.