<p>Individuals with profound and multiple disability (PMD) experience more than one type of disability, typically severe to profound intellectual disability and significant motoric impairment. These complex impairments negatively affect many aspects of the person’s functioning, such as daily living, academic, and social skills. Persons with PMD will often experience fluctuating levels of awareness, and often have such severe communication deficits that they rely on the use prelinguistic behaviours (PLBs) to communicate. It is often difficult for those working with these individuals to identify preferences and behavioural states indicative of engagement and motivation. As a result, these individuals often experience social isolation and a lower quality of life. The purpose of this research project was to evaluate the overall level of functioning and communicative abilities of four adolescents with PMD and identify instructional procedures that might enhance their natural method of communication, such that they are more readily understood. This was achieved through assessment and intervention based methods. First, the repertoire of forms and functions of specific PLBs in four participants with PMD were identified. Then, circumstances under which behaviours indicative of alertness and engagement were assessed. Next, the author validated the function of specific PLBs used to request the continuation or access to preferred stimuli. Subsequently, three intervention case studies were implemented to strengthen and/or enhance the PLB requesting behaviours of three participants using microswitch technology and individualised instructional strategies. Results suggested that individuals with PMD can and do demonstrate consistent PLBs used to request access to preferred stimuli. Specific PLBs of three participants were strengthened and/or enhanced, with two of these participants able to use a microswitch to activate a speech generating device to produce a communicative request. Implications of these results are discussed in terms of the overall outcomes for each participant and the challenges of implementing a whole communication assessment and intervention approach for this population of learners.</p>