I need some advice on NHibernate Session Management for a C# WinForms application. I am currently porting an application to use NHibernate. I am also employing a UnitOfWork pattern as described in the link below; http://nhforge.org/wikis/patternsandpractices/nhibernate-and-the-unit-of-work-pattern.aspx My question relates to Sessions. Can you only have one session running per thread at all times? I have a scenario in which a Session (UnitOfWork) may be open for a form shown by the application but the user opens another form (i.e. Tools - Options) which I would like to have its own UnitOfWork. Clearly in this instance it would make more sense to open another Session for the "Tools - Options" form and not use the currently open session for the underlying form. Can we have a Dictionary of Sessions on the one thread? Any advice on session management is appreciated.