This article presents the results of a comparison between the validity of the SCL anxiety, phobic anxiety and depression scales and the GHQ-28 anxiety-/insomnia and severe depression scales in a psychiatric outpatient population. Validity was studied at a categorical level with DSM-III diagnosis, and at a dimensional level with a prototypical anxiety and a prototypical depression scale. The SCL anxiety and depression scales and the GHQ depression scale all showed good convergent and divergent validity, however the GHQ anxiety/insomnia scale showed neither convergent nor divergent validity. It is concluded that as a screening instrument, the relative shortness of the GHQ-28 is a considerable advantage over the SCL-90. However, the GHQ-12 may be an even better alternative. As a multi dimensional measure of psychopathology, the SCL-90 is to be preferred, because it covers more dimensions. If one is interested in anxiety, the SCL-90 also seems the better choice.