The aim of this study was to determine the psychometric properties (especially validity and reliability) of the French language version of the Calgary Depression Scale for Schizophrenia (CDSS) in schizophrenic patients. Ninety-five subjects who met DSM-IV criteria for schizophrenia were enrolled. The studies of the internal structural validity and of the reliability (internal consistency) showed that some items from the CDSS (early awakening and guilty ideas of reference) must be discussed in the constitution of this scale. The total score of the CDSS was significantly correlated with the MADRS total score, the HDRS total score, and the depression item (G6) on the PANSS, which suggests that the CDSS is a valid instrument for the assessment of depression in schizophrenia. The existence of a significant correlation between the CDSS total score and the PANSS positive sub-scale suggests a possible relationship between positive and depressive symptoms in schizophrenia.