In the present study the psychometric properties of the Catalan version of Brebner's Personal State Questionnaire (PSQ) were investigatedin a sample of 280 college students. The PSQ showed a high internal consistency and a single factor structure. Concurrent validity analyses conducted using the Eysenck Personality Questionnaire (EPQ), the Positive and Negative Affect Schedule (PANAS) andthe Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ) showed results consistent with theory. The best predictor of happiness was positive affect. Our results suggest that the PSQ is a valid and reliable measure of happiness and that it could be useful for research into this construct. © 2002 Elsevier Science Ltd. All rights reserved.