What does deaccessioning in museums of cultural history and art museums have in common? What are the differences in deaccessioning needs and practices between museums of different kinds? This web publication in English is based on two joint projects on deaccessioning involving three museums of cultural history and three art museums and their web publications in Finnish from 2015 and 2016. In the first project, the cultural history museums compiled tools for deaccessioning in accordance with museum ethics. The second project focused on the views of art museums regarding deaccessioning and the joint challenges in this area faced by all museums.