A monitor support assembly having an internal cable raceway. The support assembly includes a pole mount that can be secured to a desk or table top or to a vertical wall or furniture panel, a rotatable knuckle joint at the upper end of the pole mount, and a quick-release mount for a monitor or other peripheral device. The assembly may also include nonarticulatable and vertical members, connected to each other and to the pole mount with knuckle joints that include internal sleeves. One or more cables, with plugs attached, can be inserted into the cable raceway and joints without disassembling the monitor support. The assembly may have interchangeable parts to provide different lengths for the nonarticulatable and vertical members.