An improved external trial stimulator provides neurostimulation functionality for implanted medical electrodes prior to implantation of an implantable neurostimulator. The external trial stimulator is housed in a four-part housing that provides mechanical and electrostatic discharge protection for the electronics mounted in a central frame of the housing. Connectors attached to leads from the electrodes connect to contacts that are recessed in the housing through ports that are centered for easy access. Multiple indicators provide information to users of the external trial stimulator.