Thanks Davido for the reply. So I downloaded and installed the GMP library. After doing so I tried to install the Math::GMP module again. received the same error. "can't find -lgmp". I am using OS X Lion so I do not know if this changes anything. I have read through the man page on perl. It looks like I am doing all the correct things but still can't get this module to install. I installed the library using the correct procedures and it looked like it installed properly with no errors and it passed all of the "make test" tests. Any suggestions? And thanks again for the help.