Within the domain of developmental psychopathology, increasing interest has emerged regarding parental perceptions about several childhood disorders. This interest stems from the assumption that parental interpretations of and reactions to children�s abnormal behaviour may mediate the outcome of this behaviour and influence treatment effectiveness. Within this framework, parents� and teachers� causal attributions about Attention Deficit / Hyperactivity Disorder (AD/HD) have been particularly studied (Johnston & Freeman, 1997; Johnston et al., 1992). Nevertheless, the child�s sex has rarely been taken into account and causal attributions were the only kind of cognitions included in these studies. This poster presents a theoretical model that encompasses several cognitions regarding AD/HD, takes into account the child�s sex and links these factors with referral attitudes, socialisation practices and sex differences in prevalence rates of AD/HD. This integrative model consists of three stages. At the first stage, factors that might influence parental perceptions about AD/HD in boys and girls are examined. At the second stage, possible interactions of these perceptions with differential parenting practices towards boys and girls are presented. At the third stage, the mediating role of differential parenting practices towards boys and girls for the sex differences in prevalence rates of AD/HD is explained. Preliminary research findings regarding the first stage of this model are reported (Maniadaki et al., 2003). The aim of this model is to serve as a theoretical basis for future research regarding the role of adult cognitions in the development of childhood psychopathology and of sex differences in the prevalence rates of several childhood disorders.