Objective. To assess the relationship between normal personality traits and obsessive-compulsive (OC) phenomena in individuals with subdinical OC problems and patients whose problems met diagnostic criteria for obsessive-compulsive disorder (OCD). Method. In Study 1, 25 healthy volunteers with high scores on the Padua Inventory (PI) and 28 controls with low scores on the PI were compared on the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ), the Eysenck Personality Questionnaire (EPQ), and measures of depression and state anxiety. In Study 2, 56 treatment-seeking participants meeting DSM-IV criteria for OCD and 40 healthy volunteers of similar sociodemographic characteristics were compared on the same measures. Results. Both individuals with subdinical OC problems and OCD patients scored significantly higher than their respective control groups on sensitivity to punishment, neuroticism and psychoticism. OCD patients, but not individuals with subclinical OC problems, scored lower in extraversion than their respective controls. Neuroticism was the strongest predictor of high scores on the PI in Study 1, while psychoticism was the strongest predictor of the presence of an OCD diagnosis in Study 2. Conclusion. Healthy participants with high scores on OC measures and OCD patients share various personality traits but can also be distinguished according to the level of extraversion, neuroticism and psychoticism. © 2004 The British Psychological Society.