This volume summarizes the scientific contributions presented at the 6th Meeting on Genetics and Cellular Biology of Basidiomycetes held in Pamplona (Spain) from June 3rd to 6th, 2005. The book includes full length papers covering, as well as the abstracts of all the oral communications and posters presented in the sessions. The scientific program included sessions focused on genetics and breeding, genome Analysis, Cellular and Molecular biology, Industrial Applications, Plant and Animal Pathogens, and Biodiversity.