A growing number of publications indicates presence of significant deficits in social cognition in patients with anorexia nervosa (AN). These deficits appear to be comparable in qualitative and quantitative dimension with impairment of the same functions among people with Asperger syndrome (AS). The aim of this study is to identify subject areas in the field of impairment of social cognition processes among people with Asperger syndrome and anorexia nervosa taking into consideration the potential contribution of genetic pathways of oxytocin and vasopressin in the pathogenesis of these diseases. In the first part of the paper a systematic analysis of studies aimed at the evaluation of the processes of social cognition among patients with AN and AS has been carried out. The results of a significant number of studies confirm the presence of deficits in social cognition in AN and AS. In addition, among patients with AN and AS there exists a similar structure and distribution of the brain functions in regions responsible for social cognition. The second part of the paper describes the role of the oxytocin-vasopressin system (OT-AVP) in the processes of social cognition in AN and AS. Its genetic basis and the possible importance of single nucleotide polymorphisms within the genes: OXT, AVP, CD38, OXTR, AVPR1A and LNPEP have also been presented.