I assume you install Erlang via Macports so if you install it via any other mean, something will vary (I used to install it, along with everything else, from source; but currently the Macports is just easier).
The setup is simply adding the following lines into your ~/.emacs file
(setq load-path (cons "/opt/local/lib/erlang/lib/tools-2.6.4/emacs" load-path)) (setq erlang-root-dir "/opt/local/lib/erlang") (setq exec-path (cons "/opt/local/lib/erlang/bin" exec-path)) (require 'erlang-start)
Please note that the actual path may vary from installation to installation (version numbers, most probably). So check yours.