Examining teachers attitudes/perceptions and their influence on behaviour can be an important step in understanding the psychosocial factors affecting teachers use of Information and Communication Technology in teaching. This study attempted to provide such an understanding by elaborating Ajzen s theory of planned behaviour (TPB), a widely applied psychosocial theory in modeling behaviours. In this study, the TPB was modified by (1) decomposing each of the three types of beliefs into two dimensions respectively, and (2) incorporating external variables age, sex, subject taught, teaching experience, teaching period, qualification, level of class, classroom access, and computer laboratory access.Using a survey questionnaire, data were collected from a total of 1,040 secondary school teachers in eighteen government schools in Negara Brunei Darussalam. It was found that by augmenting teachers positive attitudes towards the use of ICT and supporting them technically and personally could encourage teachers to increase the use of ICT in their teaching.