Down Syndrome (DS) is a genetic disorder associated with craniofacial features that may impact speech intelligibility and cause communication breakdown. Speech intervention has not been investigated in-depth in adults with DS due to the notion that motoric deficits are insensitive to therapy. This review seeks to identify literature pertaining to poor speech intelligibility as a component of communication deficits in this population for the purpose of informing clinical services. The results identified underlying articulatory characteristics that affect the quality and intelligibility of verbal output as well as the positive effect of speech therapy on intelligibility. The literature supports the significance of focusing on motoric-based intervention in adults with DS as well as the need for further research regarding clinical implications.