We analysed relationships between tobacco smoking and schizotypal or borderline personality traits. Three-hundred and sixty healthy adults gave information about their smoking habits and completed a computerised personality questionnaire. Schizotypal and borderline traits correlated with tobacco smoking. These correlations remained significant in analyses which covaried age, gender, educational level, neuroticism and psychoticism. The associations of tobacco smoking with schizotypal and borderline traits may illuminate the relationships of smoking and schizotypy with clinical disorders, such as schizophrenia.