Introduction: Borderline personality disorder (BPD) is a common and severe mental illness. Early detection is important and reliable screening instruments are required. To date, however, there has been no evidence of any specific BPD screening tool validated for the Spanish-speaking population. The McLean Screening Instrument for Borderline Personality Disorder (MSI-BPD) is a 10-item self-report questionnaire that can detect the presence of BPD in a reliable and quick manner. The aim of the present study is the validation of the MSI-BPD for its use in the Spanish-speaking population. Method: Psychometric properties of the MSI-BPD Spanish version were examined in a sample of 344 participants (170 outpatients with the possible diagnosis of BPD and 174 healthy controls). Results: Exploratory factor analysis revealed the existence of a bi-factorial structure. The scale showed a high internal consistency (KR-20 = 0.873) and an optimal test-retest reliability (ICC = 0.87). Using logistic regression analyses and taking the DIB-R as reference, a best cut-off of 7 was determined, obtaining a good sensitivity (0.71) and specificity (0.68). The area under the curve, was 0.742 (95% CI 0.660-0.824). The discriminant analysis showed a classification ability of 72.8%. Conclusions: The Spanish version of the MSI-BPD has good psychometric properties as a measure for the screening of BPD. Its ease and quickness of use make it valuable to detect the presence of BPD in clinical and research settings. (C) 2016 SEP y SEPB. Published by Elsevier Espana, S.L.U. All rights reserved.