The objective of this study was to analyze the psychometric properties of the Spanish version of the Eysenck Personality Questionnaire Revised-Abbreviated (EPQR-A) in informal caregivers. Trained, independent evaluators administered the EPQR-A and evaluated informal caregivers' depressive symptoms, automatic negative thoughts, self-efficacy, and pleasant social contacts, and clinical experts assessed major depressive episode in 592 caregivers (87.2% women, mean age 55.4 years). Women scored significantly higher on Neuroticism than men (p < .001). Subscale internal consistencies were .77 for Neuroticism, .75 for Extraversion, .47 for Sincerity; and .24 for Psychoticism. These four factors accounted for 38.1% of total variance. However, a three-factor model (excluding Psychoticism) better fit the data. Neuroticism was significantly, inversely correlated with both self-efficacy (r = -.35) and pleasant social contacts (r = -.22), and positively correlated with both depressive symptoms (r = .59) and negative thoughts (r = .53). Extraversion was significantly, inversely correlated with both depressive symptoms (r = -.22) and negative thoughts (r = -.22), and positively correlated with both self-efficacy (r = .36) and pleasant social contacts (r = .16). A cutoff score of 4 on Neuroticism suitably discriminated between depressed and non-depressed informal caregivers (sensitivity = 68.1%, specificity = 79.9%).