Premorbid competence has come to be considered an important dimension in predicting outcome in schizophrenia. From the growing number of social adjustment scales, this study focused on the four instruments that are currently used to assess premorbid competence specifically. The usefulness of these instruments was compared using the degree of inter-rater reliability and scale intercorrelation. Although the concept of premorbid adjustment appears increasingly complex, consisting of stages of adjustment and different levels for a single patient, at present the Phillips Scale has the best relative accuracy and clinical applicability.