no, nunit does not work nor do any other frameworks. the intent of monodroid and monotouch is to provide a .net development environment that allows you to easily port business logic between different environments. as a result you can't really test android/ios specific code, but you can test generic .net business logic code. in the monodroid projects that i write, i create 3 projects in the solution, one is the android project, another is a .net library that holds all of my non-android specific logic and the final project is a nUnit test library against the .net library. I then add my logic code files into the android project with linked files. monodroid project files can not be tested, but .net codes files linked into monodroid projects can be tested with what ever framework you choose.