Recent studies have shown that unsafe driver acts can be classified into two distinct categories (i.e.. errors and violations) entailing different measures for reducing road traffic accidents. A survey of over 1,400 drivers in Greece is reported in which a variety of aberrant driving behaviours have been identified. The present study has confirmed the results of earlier studies in the driving populations of Britain. Australia and Sweden that errors and violations are the major determinants in the factor structure of aberrant behaviours. Three types of violations were identified including, highway code-, aggressive- and parking-violations (or situational violations). Mistakes and lapses were two major forms of errors. The factor analysis identified another two classes of behaviour that could not be accounted for very well by the error-violation distinction. One class of behaviours referred to a state of low preparedness and negligence while the other class referred to communication errors and 'social disregard' for the other road users. Each class of behaviour was found to have different demographic correlates. Finally, accident liability was predicted by self-reported tendency to commit highway-code violations, but not by tendency to make errors due to failures of judgement (i.e.. mistakes) or lapses. Aggressive violations were significantly related to involvement in speeding convictions and law-breaking whilst highway-code violations were related to speeding convictions only.