A rail system (9) for an overhead hoist system (1) suspended from the rail system (9), and wherein the rail system (9) includes a primary rail (7) which is a four-edged profile with hollow cross-section (17) and a longitudinal slot (18) at the bottom, which the slot (18) and the hollow cross-section (17) are adapted for receiving and supporting part of the suspended hoist system (1), wherein the rail system (1) includes at least one angular secondary rail (19) which on one leg (20) thereof is provided connecting means (21) that interact with connecting means (22) at the side of the primary rail (7), and which on its other leg (23) is provided a support surface (24) for supporting an adjacent ceiling board (25).