Attention-Deficit/Hyperactivity Disorder (ADHD) has been identified as one of the most common behavioral disorders in childhood. The main objective of this study was analyzing the current situation of supporting children with ADHD in mainstream schools in Sri Lanka; especially how Sri Lankan primary school teachers support such children in overcoming their barriers to learning, behavior, and social relationships. A qualitative research study was conducted with ten Sri Lankan primary school teachers.The main findings of the study showed that all the primary school teachers who took part in the study did not have a satisfactory knowledge and training on educating children with ADHD traits. They currently face many difficulties when teaching children with ADHD traits in the mainstream classroom due to not having enough resources, support and guidance from relevant authorities. The finding of the study will be useful to improve or develop the education system of ADHD children in Sri Lanka, since no research study has been conducted so far regarding this topic. The research study reveals that the need for raising awareness among Sri Lankan primary school teachers on ADHD and providing enough facilities for mainstream schools so that teachers can provide a proper education for such children.