The present study addresses the question of equality of access, as it relates to waiting time for specialised mental health treatment for children and adolescents. The aim was to investigate whether demographic, clinical factors and service-related factors were associated with waiting time. Data was based on a documentation system in which all Norwegian children and adolescents receiving specialised mental health services were recorded. The analysis was based on a sample of 6497 children, who were referred for, and received, outpatient treatment in 2001, and for whom there was a complete data-set on dates for referral and first appointment at the clinic. The following factors were included for analysis: age at referral, gender, reason for referral and referring agent, place of residence, as well two aspects related to the clinic providing services (i.e. mean number of consultations provided per patient per year, and mean number of consultations done by one therapist per year). Analysis of variance, Student's t-tests and logistic regression analysis were applied. Children aged 6-12 years, and children with externalised behaviour disorders were statistically significantly more likely to wait longer for services as compared with children in the other age groups, and with other disorders. Furthermore, children referred from the school sector waited statistically significantly longer for treatment than those referred from other agencies. Results also suggest that the waiting time varies with how available resources and treatment capacity of the outpatient clinic is utilised. Waiting time for services is an important indicator of the accessibility of services, and should be included in evaluations of national mental health reforms. This study suggests unevenness in access to services, which is related both to clinical-demographical characteristics as well as to service-related aspects of individual clinics. Efforts should be made to break down barriers to care that are related to unequal access to mental health treatment for children and adolescents.