This study aims to evaluate rendered mental health services for children and adolescents through the investigation of those factors which are related to non-compliance with therapy and which affect treatment outcome. Data were collected from the files of all new cases who applied to a Community Mental Health Centre in Athens during 2000-2002 (N = 363). For each case, the following factors were examined: age, sex, family situation, parents' educational level, referral source, child's psychiatric and psychosocial diagnoses, type of proposed therapy, phase at which termination of therapy occurred and outcome. Around 45.7% of the sample did not complete therapy. The probability of treatment compliance increased when the patient was male, with a diagnosis of a specific developmental disorder, treated in a well-structured therapy programme, was from a healthy family environment and his mother was better educated. On the contrary, an adverse family situation (one-parent family, inadequate parental supervision) and the female sex had a negative association with treatment compliance. Most of the cases discontinued their treatment upon completion of the diagnostic procedure. Referral source did not influence treatment compliance. Evaluation of our service has shown that more attention should be paid to less-educated families and those in adverse situations, particularly when the patient is female.