The influence of private self-consciousness on the components of Ajzen and Fishbein's attitude model (attitude and subjective norm) is analysed. The impact of past behaviour on both current behaviour and behavioural intention is also studied. This model was applied to the prediction of voting intention and reported behaviour in the Spanish Parliamentary elections held in 1989, Attitude showed stronger influence than subjective norm on behavioural intention for subjects with a higher private self-consciousness. The opposite was true for subjects having a lower private self-consciousness. Past behaviour had a significant influence on both behavioural intention and behaviour.