The basic aim of the study is to determine whether there are any gender differences in the assessed symptoms of students (impulsivity-hyperactivity, inattention, emotional problems, unsociableness) whom teachers might consider to have an ADHD disorder. In accordance with the accompanying goals, empirical work had a total of four hypotheses. The set hypothesis that there are differences in the assessed symptoms of students whom teachers might consider to have an ADHD disorder has been partially confirmed. 242 interviewees participated in the conducted survey. These were primary school teachers from five counties of the Republic of Croatia: Koprivnica-Križevci, Sisak-Moslavina, Varaždin, Primorje-Gorski Kotar and Međimurje County. Data collection was conducted in two phases: Check list of female or male student’s behaviour (Merrell and Tymms, 2013) for sample determination and Teacher’s Questionnaire. Through factor analysis of the scale of behavioural symptoms of the students, four dimensions were obtained: 1_Impulsivity-hyperactivity, 2_Emotional problems, 3_ Inattention and 4_Unsociableness. The methods used to test hypotheses were: descriptive, correlative and differential. According to the basic research findings, it was confirmed that there are certain differences between boys and girls having ADHD disorders. The prevalence of boys had already been established by the formation of the sample, in the ratio between 5:1 to 6:1. Also, significant difference can be seen in emotional problems. Girls more often than boys express emotional instability. The results also show that: the younger the students, the greater the impulsivity-hyperactivity and the unsociableness. Inattention is also symptom which is most commonly encountered among students, but also assessed by the male/female teacher, with female teachers being those who most often notice it. Both groups of teachers, men and women, equally assess students according to the remaining dimensions of the scale of the student's behavioural symptoms.