A slide-out unit drive assembly for a vehicle body having an opening formed in an exterior wall and a reciprocable slide-out unit disposed in the opening and slidable between a retracted position and an extended position. Sliding movement of the slide-out unit is controlled by the drive assembly at least partially arranged within the jambs. The drive assembly may include one or more drive cables extending connected to the slide-out. The drive assembly may include drive chain that actuates one or more of the drive cables, or the drive assembly may include a drive nut that actuates one or more of the drive cables, or the drive assembly may include a block and tackle assembly that actuates one or more of the drive cables. Sliding movement of the slide-out unit may be either motor driven or manually powered.