The present study attempts to investigate the applicability of the TAM model in the Arab context and to extend TAM with three moderating/interacting human factors. Using a survey sample collected from 722 knowledge workers using desktop computer applications on a voluntary basis in Saudi Arabia, this study sought empirical support for testing the basic structure of TAM. Toward that, the study was successful as the structure of TAM holds well in the Saudi settings. This study also empirically examined an extended TAM by incorporating gender, age and educational level as moderators of the model’s core relationships. Our findings emphasize that most of the key relationships in the model are moderated. Specifically, age moderates all the influences of computers usefulness and ease of use on attitudes and intention to use. However, gender and educational level only moderate the influence of ease of use on attitudes.Implications for management and practice of these findings are discussed.