Background.- Child psychiatric disorders are a priority in the worldwide mental health agenda based on its prevalence, impact and continuity in adulthood.

Aims.- To review some relevant issues concerning evidence and experience that might support changes of the classification of child mental disorders and mental retardation.

Methods.- This is a selective review covering the following topics: a) the role of a developmental perspective in future classification systems; b) integrating DSM/ICD criteria; c) cross-cultural issues; d) mental retardation beyond just renaming; e) Problems in classification systems that cross-cut child mental disorders (dimensional versus categorical diagnosis; role of information source, and the impact of gender in diagnoses); f) Specific diagnostic problems in the classification of some child mental disorders.

Results.- Our findings suggest that special attention should be given to include a more developmental perspective in diagnostic systems, as well as to provide more cross-cultural and gender sensitive diagnostic criteria. In addition, an effort to improve cross-talk between ICD and DSM and to include evidencebased criteria in these systems should be pursued. However, the final product needs to be easily translated to clinical settings.

Conclusion.- Although we have accumulated a substantial load of evidence and experience supporting changes of the classification of child mental disorders and mental retardation, much more research is needed.