Parental perceptions regarding child problem behaviour have been identified as key elements in the referral process to Child Mental Health Services. As early identification of any problem behaviour is crucial for diagnosis and treatment, this study aims to examine whether parents of preschoolers who present Attention Deficit / Hyperactivity Disorder (AD/HD) symptoms perceive them as abnormal and to compare their perceptions with those of parents whose children do not display such behaviours. Mothers and fathers of 295 preschoolers, aged 4-6, enrolled in kindergartens in Athens completed: a) the Strengths and Difficulties Questionnaire (SDQ; Goodman, 1997) for the screening of AD/HD in their child and b) a questionnaire composed by a vignette displaying a five-year old child presenting AD/HD symptoms, and three rating scales assessing perceptions of the nature of these symptoms. Results showed a main effect of the existence of a child presenting AD/HD symptoms in the family on parental perceptions regarding the nature of these symptoms when present in an imaginary child described in a vignette. Specifically, it was found that parents who had been acquainted with such symptoms through their own child?s behaviour, perceived AD/HD symptoms as less indicative of a problem compared to parents whose child was not identified as displaying AD/HD symptoms. To conclude, parents whose preschool child displays AD/HD symptoms frequently tend to perceive these behaviours as normal developmental characteristics. Such perceptions may delay the referral of the child to the specialist and the diagnosis of the disorder and deprive the child of the opportunity to receive early treatment. The increased responsibility of pediatricians and nursery teachers in this regard is discussed.