There are some NHibernate add-on to do automated mapping, such as NHibenrate Attributes,Active Record and FluentHibernate. I don't really like those libraries, because that sounds adding another layer on ORM. I have some double on the speed. Moreover, if you are lazy to create xml mapping files, there are a number of code generators in the market. They can generate those xml mapping files from your database schema. I don't know why we need to introduce another layer on ORM!