Attention-deficit/hyperactivity disorder (ADHD) is a common childhood neurodevelopmental condition with early-onset and affects children worldwide. However, there is a variation in prevalence across different countries. In Nigeria, there is a paucity of information on the prevalence of ADHD and its relationship with intelligence quotient. The study aimed to determine the prevalence of ADHD among primary school pupils in Ikot Ekpene, Akwa Ibom State and its relationship to their intelligence quotient. This was a cross-sectional study conducted between April and July 2018 among 1174 primary school pupils aged 6-12 years selected from twelve primary schools in Ikot Ekpene Local Government Area of Akwa Ibom State. Vanderbilt Rating Scale for both teachers and parents was administered by teachers and parents of the selected pupils and the prevalence of ADHD was determined. Parents also filled a proforma on the socio-demographic characteristics of the selected pupils. The intelligence quotients of the pupils with ADHD and their controls were assessed using the Draw-A-Person Test (DAPT). The intelligence quotients of pupils with ADHD were compared with that of controls without ADHD matched for age, gender, and socioeconomic status. One hundred and forty-six (12.4%, 95% CI 10.5-14.3) of the pupils met the criteria for the diagnosis of ADHD using the teacher’s scale, while 8.5% (95% CI 6.9-10.1) met the criteria for the diagnosis of ADHD using the parent’s scale. Of the three different subtypes of ADHD, hyperactive subtype was the most prevalent subtype on both teacher’s and parent’s scales (52.7% and 46% respectively). Inattentive subtype was 32.9% and 33% on teachers and parents scale respectively, while the least prevalent was the combined subtype (14.4% and 21%) on both teachers and parents scale respectively. The mean age of the pupils with ADHD on the teacher’s scale was 9.3±1.7 years and 9.8±1.7 years on parent’s scale. Attention deficit hyperactivity disorder among pupils in Ikot Ekpene showed a male preponderance (56.2%) on teachers scale and 55% on parents scale (p = 0.725). The prevalence of ADHD was significantly higher in pupils from low socio-economic class on both teachers and parents scale (66.4% and 64% respectively), p= 0,0001. The mean IQ score of the pupils with ADHD was significantly lower than that of controls on teacher’s scale (IQ score of pupils with ADHD = 74.7±29.2, Control = 103.5±33.0, p=0.0001) Also, Pupils with ADHD on parent’s scale had significantly lower IQ compared to the controls (IQ score of pupils with ADHD = 76.86±231.9, Control = 106.4±35.4, p= 0.0001). Fifty-four percent of the pupils with ADHD who had low IQ had the hyperactive subtype of ADHD on teacher’s scale and 62.5% of the pupils with ADHD and low IQ also had the hyperactive subtype of ADHD on parent’s scale. It is concluded that the prevalence of ADHD among primary school population in Ikot Ekpene is 12.4% and 8.5% using teacher’s and parent’s scales respectively. The mean IQ of the pupils with ADHD was significantly lower than that of controls. It is recommended that a screening test for ADHD under the school health programme should be carried out on pupils in primary school to identify pupils with ADHD. There is a need for awareness creation concerning ADHD in the general population as this will help draw the attention of parents and caregivers to it and ensure early identification and appropriate intervention.