Objective: Dropout from the ongoing treatment is defined as premature termination of the treatment against the clinician's advice. Dropout may lead to insufficient treatment, endurance of the disorder and worse quality of life. The aim of the present study is to investigate relationship of dropout with a list of possible predictive factors including; diagnosis, treatment modality, previous contact with services and child and family-related sociodemographic characteristics related to the child and their families. Methods: The sample consisted of a total of 954 children and adolescents, aged 6-18 years, attended to Bezmialem University Hospital, child and adolescent psychiatry outpatient clinic between July 2015 and May 2016. A semi-structured clinical examination was used to endorse clinical diagnosis. Results: Dropout rate in the total sample was 52.0% (29.0% for early; 23.0% for late drop out). Almost 70% of the subjects, who were treated with a combination of medication and psychotherapy continued with their treatment. Diagnosis of an externalizing disorder or attention deficit hyperactivity disorder (ADHD) were significantly higher in the late dropout group, while internalizing disorder was higher in those who engaged with treatment. Mother's higher education attainment showed positive relationship with service engagement. Previous psychiatric diagnosis in the child was an independent protective factor for discontinuation of treatment (OR=1.251,CI= 1.05-1.49, p=0.011). In terms of the treatment modalities, most of those who were treated with medication only dropped out late (74.6%), however pharmacological treatment on its own also appeared to be an independent predictor of dropout (OR=0.586, CI=0.47-0.72, p<0.001). Discussion: Dropout rates were higher than previous studies. Motivation to contact the service and treatment modality offered to the patient can predict their service engagement. Further local studies are needed to address factors related to dropout and the role of the current mental health system and lack of resources in poor service engagement needs to be clarified.