An electric stair lift system for transporting people and/or cargo up and down a flight of stairs includes a pair of parallel rails, a platform that is slidably engaged with the rails, an electric winch with a take-up spool, and pair of straps attached between the slidable platform and the take-up spool of the winch. In a preferred embodiment, the electric stair lift system is portable, so that it may be installed in such a way that it may be easily removed, stored and transported, as desired.