An anti-friction bearing unit (1), configured at least as a two-row anti-friction bearing with at least one outer ring (4a, 4b) and at least two inner rings (5a, 5b), between which rolling bodies (6a, 6b) are guided on raceways of the bearing rings (4a, 4b; 5a, 5b). A clip ring (14) that engages into annular grooves (12a, 12b) of axially extended sections (8a, 8b) of the adjacent inner rings (5a, 5b) is provided for securing an axial position of the inner rings (5a, 5b). The radially pre-stressed clip ring (14) of U-shaped design is arranged in a non-positive manner on an intermediate step (13) of the inner ring (5a) in a pre-mounting position and can be pushed from there into an end position. In matching positions of the flanks (15a, 15b) of the clip ring (14) and corresponding annular grooves (12a, 12b) of the extended sections (8a, 8b), the clip ring (14) latches in a positively locking manner and brings about an axial connection of both inner rings (5a, 5b).