As Meloni, Federici, and Stella (2011) claim, the non-coding of personal factors in the International Classification of Functioning, Disability and Health could be considered as one of the most influential causes of the scarcity of scientific literature on the role of the psychologist in the field of rehabilitation in general and in the assistive technology (AT) assignment process in particular. In order to overcome this cultural barrier, in the present chapter, the professional functions of the psychologist in a centre for technical aid are described by categorising the necessary skills into two psychological dimensions: expertise on personal factors and ability in the field of human relationships and communication. The psychologist practises these competencies by pursuing three main aims: i) to empower the user/client to achieve a greater awareness of his or her own resources and to reach the optimum level of satisfaction by choosing and adopting the appropriate AT solution; ii) to support family members or caregivers in providing effective support to disabled people; and iii) to help the multidisciplinary team’s centre improve professional relationships and mutual communication and, consequently, the effectiveness and efficiency of the centre itself. The tools which the psychologist uses are not only the administration and interpretation of the main instruments for clinical and behavioural assessment, but also the ability to listen, receive and understand within the professional psychological relationships in which the psychologist himself or herself is involved in a centre for technical aid.