The purpose of this article is to investigate the factors influencing the intention to use the Internet to book tourism products online in Tunisian context. To this end, the authors selected the Decomposed Theory of Planned Behavior (DTPB) to help account for the intention to book online. The authors conduct an online survey. Data was obtained from 158 questionnaires and analyzed through regression. The study demonstrated the importance of causal relationships between predictor variables and the dependent variable, namely the intention to book online. A novel result, perceived usefulness does not admit a positive impact on the attitude towards online booking. Thus, the study has confirmed the explanatory power of the DTPB model in accounting for consumers' behavioral intention in the context of e-tourism.