Background: This study presents a new questionnaire to assess schema modes: the Schema Mode Inventory (SMI). Method: First, the construction of the short SMI (118 items) was described. Second, the psychometric properties of this short SMI were assessed. More specifically, its factor structure, internal reliability, inter-correlations between the subscales, test-retest reliability and monotonically increase of the modes were tested. This was done in a sample of N = 863 non-patients, Axis I and Axis II patients. Results: Results indicated a 14-factor structure of the short SMI, acceptable internal consistencies of the 14 subscales (Cronbach alpha's from .79 to .96), adequate test-retest reliability and moderate construct validity. Certain modes were predicted by a combination of the severity of Axis land II disorders, while other modes were mainly predicted by Axis II pathology. Conclusions: The psychometric results indicate that the short SMI is a valuable measure that can be of use for mode assessment in SFT.