As part of an epidemiological study, the diagnoses of children with psychiatric disorders at age 13 were determined according to the criteria of both the ICD-9-oriented Multi-Axial Classification Scheme (MAS) and the Diagnostic and Statistical Manual, 3rd ed. (DSM-III). A comparison of the diagnosis pairs showed that in most cases (76%) comparable diagnostic categories had been selected. Discrepancies were found mainly in the use of the diagnoses "conduct disorder" (ICD, DSM-III: 312) and "age-specific emotional disorder" (ICD, DSM-III: 313). Severity of disorder had little impact on the extent of agreement between the two classification procedures. In an additional analysis the comparability of the threshold values used in the case definition criteria in the two systems was examined. The DSM-III criteria yielded 11 more cases of psychiatric disorder than the MAS criteria, 10 of these with the diagnosis of "attentional deficit" (ICD, DSM-III: 314).