Obsessions are repetitive and continuous thoughts, impulses, or images which experienced as forcibly, coming unintentionally, and are causing significant anxiety or distress in most people. Compulsions are defined as repetitive behaviors or mental acts that occurs in response to people's obsession or felt strictly forced according to the rules that must be followed. Until recent studies, researchers believed that obsessive-compulsive disorder (OCD) is rare in childhood, but new studies show that it's not rare as believed. Insight in OCD is defined as acceptance of obsessions and compulsions unreasonable and excessive. Insight of some children and young people with OCD can be poor. Poor insight in OCD is the determinant of poor response to treatment. In literature, there is not enought information about poor insight in children. So, a lot of questions still remain unanswered and there is a need to work on insight in children. In this case report, it is aimed to discuss the process of diagnose and treatment of a patient who is fifteen years old and diagnosed as OCD with poor insight.