A zoom lens barrel includes a cam ring which is driven to rotate; a first lens frame which is positioned around the cam ring, supports a frontmost lens group of a zoom lens system, and includes a first cam follower; a light-shield exterior ring positioned around the first lens frame, and includes a second cam follower; and first and second outer cam grooves formed on an outer peripheral surface of the cam ring so that the first and second cam followers are engaged in the first and second outer cam grooves, respectively. The second cam follower is engaged in the second outer cam groove through a linear guide slot formed on the first lens frame. Zooming ranges of the first and second outer cam grooves are shaped so as to move the first lens frame and the light-shield exterior ring in the same moving path.