A raising mechanism of a movable lower grill grid formed with a hand crank mounted to lateral columns of a frame of a barbecue grill and a worm provided in a middle point of the hand crank. A cross-sectional rotary axis is arranged below a fixed upper grill grid and a worm wheel with one end engages the worm. Pulleys are mounted to respective ends of the axis. Steel cables include ends mounted to the pulleys and lower ends mounted to lateral tabs of the lower grill grid. The mechanism also includes a casing for housing and protecting the mechanism.