|Abstract||Objective: The objective of the present study was to find the prevalence of attention deficit hyperactivity (ADH) symptoms in a sample of primary schoolchildren in Qatar and investigate the behaviour of the children with and without ADH symptoms in a highly consanguineous community. Subjects and Methods: A total of 2,500 primary school students, aged 6-12 years, were randomly selected from the government primary schools, and 1,869 students (947 boys and 922 girls) gave consent to participate in this study. An Arabic questionnaire was used to collect the sociodemographic variables and a standardized Arabic version of the Conners' Teacher Rating Scale for ADH symptoms. Results: Of the 947 boys, 158 (16.7%; 95% confidence interval, CI, 14.4-19.2) and of the 922 girls, 50 (5.4%; 95% CI 4.1-7.1) scored above the cut-off (≥15) for ADH symptoms, thus giving an overall prevalence of 11.1% (95% CI 9.7-12.6). The children who had higher scores for ADH symptoms were in the age group of 6-9 years. Children who had higher scores for ADH symptoms had a poorer school performance than those with lower scores (p = 0.002). Two hundred (96.2%) children with ADH were disobedient, 126 (60.6%) noisy and hyperactive, 76 (36.5%) very cranky, 78 (37.5%) troublesome and 79 (37.9%) nervous. The logistic regression identified socio-economic condition, number of children, school performance and poor relationship between parents as the main contributors to ADH. Although the univariate analysis showed a significant relationship (p = 0.010) between ADH symptoms and consanguineous parents, logistic regression did not support this association (p = 0.075). This suggests that consanguinity has no impact on ADH children. Conclusion: The study revealed that ADH is a common problem among schoolchildren. The children with higher scores for ADH symptoms had a poorer school performance than those with lower scores. A significant difference exists between the behaviour of children with and without ADH.