It is important that depressed patients receive adequate and safe care as described in clinical guidelines. The aim of this study was to evaluate the implementation of the Dutch depression guideline for children and adolescents, and to identify factors that were associated with the uptake of the guideline recommendations. The study took place in specialised child and adolescent mental healthcare. An implementation project was initiated to enhance the implementation of the guideline. An evaluation study was performed alongside the implementation project, using structured registration forms and interviews with healthcare professionals. Six multidisciplinary teams participated in the implementation study. The records of 655 patients were analysed. After 1 year, 72 % of all eligible patients had been screened for depression and 38 % were diagnosed with the use of a diagnostic instrument. The severity of the depression was assessed in 77 % of the patients during the diagnostic process, and 41 % of the patients received the recommended intervention based on the depression severity. Of the patients that received antidepressants, 25 % received weekly checks for suicidal thoughts in the first 6 weeks. Monitoring of the patients’ response was recorded in 32 % of the patients. A wide range of factors were perceived to influence the uptake of guideline recommendations, e.g. the availability of capable professionals, available time, electronic tools and reminders, and the professionals’ skills and attitudes. With the involvement of the teams, recommendations were provided for nationwide implementation of the guideline. In conclusion, a systematic implementation programme using stepped care principles for the allocation of depression interventions seems successful, but there remains room for further improvement.