Many more boys with ADHD are seen in clinical settings, at a ratio of approximately 9 boys to every girl. While it is recognised that girls genuinely present less frequently with symptoms of ADHD, epidemiological studies suggest that the ratio is closer to 4:1 in community samples. It is apparent that significant numbers of girls with ADHD do not receive professional help.;This study investigated the influence of a child's gender on a sample of female teachers (N = 46) and mothers ( N = 61) ratings of concern about the inattentive, hyperactive and impulsive behaviours associated with ADHD, and the oppositional behaviours that frequently co-occur. Participants rated their concern in response to the behaviour of a fictional 7-year-old child on an amended behavioural rating scale (Conners' Rating Scale-Revised: Long version).;Teachers gave significantly higher ratings of concern in response to ADHD and oppositional behaviours for a fictional 7-year-old boy compared with those for a girl. No differences were found between mothers' ratings of concern for girls and boys.;The results are discussed in relation to previous research into the different ways in which boys and girls present with ADHD, and the effect that this might have on recognition and referral rates. The way in which the behaviours associated with ADHD are judged and rated, and possible differences in help-seeking behaviours in relation to boys and girls with ADHD are also addressed. The limitation of the study are discussed, and the implications of the findings are presented in terms of clinical practice, service design, and suggestions for future research.