A carrier bar for a motor-vehicle roof is provided at each of its ends with a supporting leg (6) having a head (5) slidably mounted within a guide rail (3) of the bar (1). The head (5) is axially movable along with a threaded stem (7) which is screwed in a threaded channel (4) of the bar (1) and can be rotated to cause a movement of the supporting leg (6) along the bar (1). The bar has a bolt (13) with an enlarged head (14) which engages a slot (15) of a hook member (12) having a hook (17) adapted to engage the side edge of a motor-vehicle roof.