A linear motion device has a first assembly and a second assembly which is linearly movable relative to the first assembly. A first rolling surface which extends in a longitudinal direction is provided on the first assembly and is situated opposite a second rolling surface provided on the second assembly. A row of rolling elements is located between the first and second rolling surfaces. The first assembly includes a single-pieced, first body and a return assembly and a return passage being provided in the first body A curved deflection passage is located entirely within the deflection assembly and connects the first rolling surface to the return passage such that the rolling elements circulate endlessly A projection that engages in the return passage is provided on the deflection assembly.