During treatment and rehabilitation process of children with mild mental retardation and associated disorders there is various data that has to be gathered and analysed, such as personal and family data, diagnosis, behaviour and prognosis. Additionally, in this paper are explained reasons and made initial efforts to add their usage of information and communications technologies to rehabilitation evaluation data. Ontologies, as modern knowledge bases, have already been developed for various domains, including the field of psychology. For a purpose of monitoring mental retardation rehabilitation process, possible use of ontologies is also explored. Ontology has been developed in Web Ontology Language using Protégé-OWL tool.