This study reports an empirical investigation of the effects of school teachers' self-efficacy and self-concept on their perceived ICT usability. It employed a descriptive survey method within an ex-post-facto research design taking 300 teachers as samples from 50 Indian schools. The findings revealed that self-efficacy and self-concept discretely had a positive effect on teachers' perceived ICT usability although self-concept was found to have a deeper impact in comparison to self-efficacy. But the two variables operated simultaneously had a more significant and stronger positive effect on the teachers' perceived ICT usability. For every 1 standard unit increase in self-efficacy and in self-concept, the perceived ICT usability will be increased by 0.95 standard units. Based on this regression output, the authors proposed the TAM3+ as an extension of the TAM3 by adding a new domain as users' 'subjective self' encompassing self-efficacy and self-concept significantly affecting their perceived ease of technology use.