Your second !PATH assignment canceled out your first ... and both assignments canceled out the default IDL Search Path, which is essential for most IDL programs. The proper syntax for appending to the default IDL Search Path (rather than ***overwriting***!) is: !PATH = !PATH + '/path/to/my/personal/idl/directory/' Before you want to issue such a reassignment, however, you should check whether the path you want to append is not already in the current path. Thus, do this: PRINT, !PATH and look over the output before you do this: !PATH = !PATH + ... I think you will see that '/usr/local/rsi/idl_6.2se/lib' is already in your path. Furthermore !PATH is only for directories that hold '.pro' and/or '.sav' files. It is not needed for directories that hold only '.dlm's, '.so's, ',dll's and '.exe's. Thus, there is no good reason to have IDL's '.../bin/bin.linux.x86/' directory in the !PATH. You need only make sure that that directory is in IDL's DLM Path. "PRINT, !DLM_PATH" will ascertain that. James Jones