A slide rail assembly includes an inner rail unit, a pair of first and second outer rails, first and second roller mounted to the inner rail unit, and third and fourth rollers mounted to the pair of first and second outer rails. The inner rail unit includes an inner substrate assembly, a pair of first bent portions provided to a first side of the inner substrate assembly, and a pair of second bent portions provided to a second side of the inner substrate assembly. The first outer rail includes a first outer substrate and a pair of third bent portions. The second outer rail includes a second outer substrate and a pair of fourth bent portions. The pair of first and second outer rails is disposed with the pairs of third and fourth bent portions facing inward, and slidable against the inner rail unit.