OBJECTIVE: to validate and evaluate the clinical utility of a Chilean spanish version of the Mood Disorder Questionnaire (MDQ), a self-report screening instrument for bipolar I and II disorders in adult outpatients of the Mood Disorders Clinic (MDC) at the Instituto Psiquiátrico Dr Jose Horwitz in Santiago, Chile. METHOD: The results of the screening were compared with the bipolar diagnosis according to the SCID I - DSM IV version, and with the clinical diagnosis in axis I and II according to DSM IV diagnostic criteria made by seniors psychiatrist who were blind to the MDQ results. RESULTS: A total of 260 patients were evaluated (68.1% women, 31.9% men), with an average age of 40.5 years. Of the total sample 25.4% had personality disorder related pathology. The sensitivity of the instrument was 0.71 and the specificity was 0.84. The internal consistency was quite high with a Cronbach α of 0.77. The scale evidenced an adequate concurrent validity in relation to SCID I (rps 0.65). The psychometric properties of the instrument changes when question 3 of the MDQ is excluded. Concomitantly, this sample demonstrated that the discriminating capacity of MDQ, varies significantly between MDQ (p=0.08) and SCID I (p<0.000) with the presence-absence of Axis II Disorders. CONCLUSION: MDQ is a reliable instrument with good sensitivity/specificity rates, to screen bipolarity in a Chilean population. The discriminating capacity to screen bipolar disorders varies significantly in the presence of axis II pathology.