A vehicle lighting unit can have an aiming mechanism with a pivot holder structure such that a pivot attached to a reflector that holds a bulb is supported by a pivot holder integrally formed with a housing while the pivot is rotatable and an adjustment bolt is provided, so that the rotation of the adjustment bolt can achieve adjustment of an optical axis by inclining the reflector. The pivot holder can include a reception seat extending in a direction perpendicular to a direction in which the pivot is inserted and having an arc-like curved surface for receiving a ball of the pivot, and a pair of claws extending in the direction perpendicular to the direction in which the pivot is inserted so as to be parallel with each other and configured to support the ball, the pair of claws being coupled to each other by an arc-shaped bridge.